My RZ-350 Holes both pistons again on Sunday morning on the Freeway @ 65MPG & just under 65MPH
Bob Nixon
Saturday for 100 mile ride in the canyon and it ran fine with no
additives in the gas or oil and prime position for the fuel on the
freerway. Same thing Sunday morning but about 10 miles in at just
under the RPM that the dynamic compression skyrockets or ~5900RPM @ 65
MPH I lost power on one side. Instead of stopping right there I road
it in fourth gear @ ~8000RPM for another 15miles until the second
piston holed and I rolled to a stop just short of my exit. I got it
into neutral and cranked it by hand and sure enough no compression.
This is the third time for burning pistons so I'm thinking the head
was never machined properly (shape & squish bands up to the center
spark plug hole) back when the piston hit the cracked cylinder wall
just above the exhaust port and hammered the piston, head and plug
into oblivion. (see original photos below)
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280369.JPG
( Original Cylinder crack above exhaust port ) Old bike and likely
rusted water after sitting mostly for 24 year with only 7000 miles on
the engine then I take it out and do a 120 MPH speed ride and
generally beat the piss out of the old gal until the above happened.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280370.JPG
Above: Hammered cylinder head from original broken piston top
hammering aluminum all the 20 miles to home on one cylinder.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280373.JPG
Damaged piston from cylinder wall crack at 20 miles of beating.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280373.JPG
Destroyed spark plug second to the left.
Obviously the head had to be built back up with weld then re-machined
to spec but I never got to see the work as the bikes was put back
together the next three times it failed. I was given the old parts but
again never saw the head work. On one failure one rod bearing seized &
bent the rod but the guy covered that under a bad repair job.
Next part is my story on how I got my bike & me back almost 24 miles
from home for $-0-.
I moved the bike on the S202 freeway as close to the edge of the
concrete as I could so no one would hit it. I moved myself another ten
feet up the gravel side and next to the off ramp that was another 10
feet above me. Next for about five minutes I sat there and planned
what to do next. I called my friend who was "maybe" going to meet me
at Starbucks at the next off ramp. We had it worked out the night
before that he would call me if he was not coming. It was still early
or before daylight, so I called him and woke him up telling him of my
problem. He said he had planned on calling me and sleeping in but
would empty his big trailer and come to my aid and would call when he
left the house & was under way some 18 miles West back down the
freeway. Then came the wait and to my astonishment for over 1/2 hour
at least 100 cars and maybe 10 bikes whooshed by without a second
look. Then a DPS cop got off the freeway ramp just opposite of me and
I thought he might have done so because he saw me, but no, he just
went left or down the street 90 degrees from the freeway. Then finally
a Mesa cop stopped after I waved my arms. He asked me if I wasy hurt
and I said no just the bike and thanks to my cell phone that help was
on the way. I don't even know now why I bothered hailing him other
than just to see if he would stop and do his "to protect & self" do
diligence thing and that he did.
After 1/2 hour a guy on a CBR1000R getting on the freeway just behind
me stopped and as soon as I saw his face we both said "Hey I know
you". Anyway he offered to go back home ( very close to where we
were ) and get his pickup then load the bike and take me home and
right out; refused the $100.00 I offered and just said people have
helped him before & it was the decent thing for one biker to do for
another. I immediately called Paul and he hadn't left yet but said he
and his son would come anyway and help load the bike and bring me some
coffee. It wasn't 15 minute and they both showed up about the same
time. It seemed like a short ride home with a bagel and a nice hot cup
of coffee. We unloaded the bike, mostly him, because of my handicaps
and he did except my full "Good Egg" card for a free breakfast and I
said I'd also buy his breakfast at TTF for the next three months but
he said it wasn't necessary. What's the moral of the story? I'm
thankful for friends and that there are still good bikers everywhere.
OBTW, another guy I knew stopped to see if he could help but I said
that help was on the way.
Finally the only thing I'm going to do to that bike is drain the
coolant and pull the head and peruse it good and take some pictures
then try to sell the bike for as much as I can. I still have the 08 SV
that would never leave me stranded even two months ago when I low
sided it and rode it home with a busted foot and sprained ankle.
Actually I only rode it 5 miles and Paul rode it the rest of the way
home and his wife drove me to the hospital for X-rays and bandaging.
Long story but it's the only way I know how to tell it.
Bob..
Andrew
"Bob Nixon" <bigre...@yahoo.com> wrote in message
news:27071b87-fb40-4f93...@37g2000yqm.googlegroups.com...
>.
Sorry to hear about this Bob.
Also sorry to hear about the lack of people stopping to check on ya.
I stop a lot, since I have a truck with a ramp I carry around.
I've helped a few people over the years.
--
Andrew
00 Daytona
00 Speed Triple
05 Squiddo
Steve Lusardi
Very nice bike in its time, but the fault is clearly a lean condition and I am afraid it is probably self inflicted. For what ever
reason you were running lean and you have done this 3 times. Don't blame the mechanic. Get a hearing aid. Detonation is very loud.
Compression doesn't skyrocket......it never changes......you overheated the motor.
Steve
"Bob Nixon" <bigre...@yahoo.com> wrote in message news:27071b87-fb40-4f93...@37g2000yqm.googlegroups.com...
Tim
> This is the last friggin' time for this POS bike. I'd taken it out
> Saturday for 100 mile ride in the canyon and it ran fine with no
> additives in the gas or oil and prime position for the fuel on the
> freerway. Same thing Sunday morning but about 10 miles in at just
> under the RPM that the dynamic compression skyrockets or ~5900RPM @ 65
> MPH I lost power on one side. Instead of stopping right there I road
> it in fourth gear @ ~8000RPM for another 15miles until the second
> piston holed and I rolled to a stop just short of my exit. I got it
> into neutral and cranked it by hand and sure enough no compression.
> This is the third time for burning pistons so I'm thinking the head
> was never machined properly (shape & squish bands up to the center
> spark plug hole) back when the piston hit the cracked cylinder wall
> just above the exhaust port and hammered the piston, head and plug
> into oblivion. (see original photos below)
If you knew that you were actually getting 65mpg on that thing, that
should have been your first warning of impending doom. Normally tuned
stock RZ350s get about 37-42 mpg on the highway. Yours is a tuned up
example getting significantly more horsepower (thus is producing
significantly more heat and should be burning significantly more
fuel). That thing is running horribly lean of you are getting 65mpg.
Racers I've raced against on RZ350s get low 20's. My own stock RZ350
on the racetrack got under 30mpg. If I got over 40mpg on the highway
at a steady 65mph on a bike like that, I would be very worried.
Of course, you knew that you were going to hole the second piston
after you'd lost the first cylinder; I assume you just neded to keep
going to get to a safe place to be stranded?
Glad you weren't hurt.
Tim
BryanUT
<snip>
Sorry to hear about that.
Thank goodness for cell phones and friends and strangers.
Ed Light
My first one holed up on the factory settings. After learning to set the
mixture properly (including proper main jet) and test for the right
spark plug heat range, it was totally reliable even after souping it up.
The plugs should show chocolate brown. If they're white it's doom from
heat. Colder plugs needed. The fastest main jet is the proper one.
--
Ed Light
Better World News TV Channel:
http://realnews.com
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Send spam to the FTC at
sp...@uce.gov
Thanks, robots.
Bob Nixon
Why would I get hurt from losing a piston, it didn't seize.
> Tim
Tim, I never, ever said it got 65 MPG. I did say it was going 65 MPH @
5900 RPM but in all my discussions about this bike I've said it gets
about 35MPG and no better. Please read my post again before flying off
the handle. The guy I had tune it on the Dyno even said he could have
made a few more HP but he didn't want to lean the bike too much
especially in the winter. I really think you owe my an appology. I do
make typo's fairly often but only one about the cop stopping that I
can see with this one.
below ia a direct quote tajen out of my post.
Same thing Sunday morning but about 10 miles in at just
> under the RPM that the dynamic compression skyrockets or ~5900RPM @ 65
> MPH
Bob..
Bob Nixon
> Bob,
> Very nice bike in its time, but the fault is clearly a lean condition and I am afraid it is probably self inflicted. For what ever
> reason you were running lean and you have done this 3 times. Don't blame the mechanic. Get a hearing aid. Detonation is very loud.
[...] snip my original post. look it up if you have any other problems
with what I said.
Steve, it's obvious you know nothing about how real world engines work
if you REALLY don't believe there is something called "dynamic
compression ratios" in both 2 and 4 stroke engines.
4 strokes have a dynamic compression ratio, in that there is something
called intake and exhaust valve overlap that tends to reduce the
geometric compression ratio at low RPM's. This all depend on the
engine and how it's tuned.
2 strokes have even more dynamic compression ratios in that the
exhaust port at idle o r@ low RPM is only 6.5-7.0 compression ratio if
you only look at port closure timing. However (look this term up and
you might learn something) the "KADDEN" tuned exhaust, similar in
function as a valveless pulse jet, re-stuffs the exhaust port over a
range of resonant frequencies to nearly twice the compression ratio or
kind of like a solid state supercharger and still dumps some exhaust
out the other end of the pipe. On the RZ-350 my pipe were mainly
resonant from 6000 to 8500RPM. (tuned on a dyno a little on the rich
side). Also, due to the exhaust power valve that dynamically changes
the exhaust post opening position as a function of RPM and throttle
position. That's the main reason two stroke have a nonlinear hit of
power when the engine speed goes from low RPM to that resonant point
or hence my reference to cruising on the freeway at 5900 RPM or just
below the RPM that the engine hits "hard on the pipe". As far as the
rest of your reply post goes, you're as full of crap as you are on
this point. For instance, with a helmet and earplugs on it's hard to
hear any pinging or much of any two stroke engine noises for that
matter. Now listen good, Steve. Unless you were just trolling. I
EXPECT an apology or some sort of retraction for your highly
ignoramous and non-empathetical response to my original post.
Bob Nixon..
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
Thanks, Andrew. It seems you're the only responder to read my post
fully.
Bob..
Bob Nixon
Thanks for your empathy, Brian.
Bob..
Bob Nixon
> Is it a two-stroker?
>
> My first one holed up on the factory settings. After learning to set the
> mixture properly (including proper main jet) and test for the right
> spark plug heat range, it was totally reliable even after souping it up.
> The plugs should show chocolate brown. If they're white it's doom from
> heat. Colder plugs needed. The fastest main jet is the proper one.
>
> --
> Ed Light
Thanks, ED but I did have this engine tuned on the rich side on a dyno
by a guy who's a two stroke expert in our area. He said he could have
gotten a few more HP more if he'd have gone one jet main jet size
smaller but was worried that this was a street bike and that I would
be riding it in the winter months as well as our hot summer months in
central, AZ.
Bob, Nixon, Chandler , AZ
Joey Tribiani
Tim, I never, ever said it got 65 MPG. I did say it was going 65 MPH @
5900 RPM but in all my discussions about this bike I've said it gets
about 35MPG and no better. Please read my post again before flying off
the handle. The guy I had tune it on the Dyno even said he could have
made a few more HP but he didn't want to lean the bike too much
especially in the winter. I really think you owe my an appology. I do
make typo's fairly often but only one about the cop stopping that I
can see with this one.
below ia a direct quote tajen out of my post.
Same thing Sunday morning but about 10 miles in at just
> under the RPM that the dynamic compression skyrockets or ~5900RPM @ 65
> MPH
Bob..
___________
I'm never one to defend Tim, unless he's in the right... Bob, you obviously
did not read the subject line you posted for this thread. for your
convenience I'll quote it... "My RZ-350 Holes both pistons again on Sunday
morning on the Freeway @65MPG & just under 65MPH".... I can see where he
believes you to have said you were getting 65MPG...... just sayin'
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
My bad for the typo in the subject line but he still should have at
least read my entire friggin' post.
Bob..
Tim M.
That's what I meant. Glad it didn't seize and put you on the ground.
Glad that it didn't coat your rear tire with oil and put you on the
ground. Glad it didn't run out of power right when a semi-trailer
was bearing down at you at 85mph like they do around here, and run
over your ass. Glad you didn't have a drunk or inattentive driver
slam into you as you worked your way over to the shoulder. In other
words, I'm glad you weren't hurt, Bob.
I'm sorry if that's simply too hard for you to understand, Bob.
> Tim, I never, ever said it got 65 MPG.
I guess I just got the wrong damn fucking impression from reading YOUR
title that said QUOTE "My RZ-350 Holes both pistons again on Sunday
morning on the Freeway @ 65MPG & just under 65MPH" UNQUOTE
I guess when you said you were "on the Freeway at 65MPG & just under
65MPH" you meant you were hauling the bike in your pick-up truck at
65mph and your pick-up truck was getting 65MPG. How incredibly
STUPID of me not to infer that from what you actually WROTE.
> I did say it was going 65 MPH @
> 5900 RPM but in all my discussions about this bike I've said it gets
> about 35MPG and no better.
Well, I guess that might be true, except in this discussion, to which
I was responding, in which you said it was getting 65MPG.
> Please read my post again before flying off
> the handle.
Maybe you should take your own advice, Bob, and read my post again
before flying off the handle. While you're doing that, Bob, perhaps
you should read YOUR OWN post again, before flying off the handle.
> The guy I had tune it on the Dyno even said he could have
> made a few more HP but he didn't want to lean the bike too much
> especially in the winter. I really think you owe my an appology.
Right, Bob. Everybody owes you an apology.
> I do make typo's fairly often but only one about the cop
> stopping that I can see with this one.
Well, I didn't see any typo's, either Bob. All I did was respond to
what you wrote.
But I won't ask you for an apology.
Tim M.
What makes you think I didn't read your "entire friggin' post," Bob.?
You didn't say ANYTHING in the post to indicate that you were NOT
getting the gas mileage you claimed in the title. You posted about
holing BOTH pistons in your RZ350. I happen to know that it is not
only possible but COMMON to hole pistons in RZ350s when those bikes
are run too lean. You gave NO ADDITIONAL information anywhere in your
post to indicate that the bike was NOT running far, far, too lean, as
your title suggested.
I did read your entire post, Bob.
It's funny. You're so defensive and so tightly wound that you even
take offense at someone responding that they are glad you weren't hurt
when your motorcycle engine stops running on the freeway.
No; correct that. Not funny.
Sad.
Joey Tribiani
"Tim M." <tomorrowat...@yahoo.com> wrote in message
news:cb391bfa-3642-4b4d...@d5g2000yqm.googlegroups.com...
>No; correct that. Not funny.
>Sad.
Definitely not the "happy Bob" we were promised a few days ago, eh?
Bob Nixon
What happened was the post was so long and I went back and edited it
so many times that Google timed me out and so I copies only the
message part and logged out ten back in again and pasted the message
part back in and when I went to retype the title it came up with the
same subject as before so I just let the software copy it back in and
didn't even bother to re-read where I made the big typo that should
have read: "My RZ-350 Holes both pistons again on Sunday morning on
the Freeway @ 65MPH (not MPG) & just under 6000RPM (not 65 MPH). Also,
Tim when I was inundated with several similar posts as you own I
became defensive. Now, Tim tell me you've never made a typing mistake
or even been stranded out on the highway before sunrise yourself and
admitted it to this group. Of course you haven't because Tim has to
keep up the "I am perfect" facade. I was even hesitant to post this to
the world myself but I decided to go ahead and be the candid person
with GOOD or BAD news that I always have given to this post hungry
group. Don't you wish you could say the same there, Timsy?,;)
Bob..
Bob Nixon
> "Tim M." <tomorrowaterolsdot...@yahoo.com> wrote in message
Would you be if your bike blew up on you, Joey. Hell, most of your
posts are responses to other's posts anyway or hardy one to chastise
me.
Bob..
Ed Light
> Thanks, ED but I did have this engine tuned on the rich side on a dyno
> by a guy who's a two stroke expert in our area. He said he could have
> gotten a few more HP more if he'd have gone one jet main jet size
> smaller
Are you sure the plug heat range wasn't too hot? What color are the plugs?
AlF
I am sorry about the RZ and the whole hassle. I just got the trailer
last Sunday - so next time you or anyone is in need just give me a buzz.
30 minutes and I will be on the spot.
as far as the typo in the subject :-) - yeah you got an on board
computer telling instant MPG on 20 old years two stroke bike - I guess a
decent motorcyclist :poke: should be able to catch it was a typo ...
anyways ...
get yourself a small Monster - just kidding :-).
actually I wonder what would be the best modern or semi-modern
equivalent of RZ-350 in terms of handling, weight and power ...
Best,
Andy
Tim M.
I sure do, Bob. Why, if I were that kind of person, I might even have
posted about my adventures with a broken down Harley-Davidson in
Knoxville, Tennessee, in June of this year, even though I knew how
much certain people in this group HATE everything Harley-related and
would be sure to take advantage of such an admission while I was
stranded out of state and had to get a hotel and everything.
Heck, I might have admitted how I couldn't even keep an old broken
down warhorse like Jimmy Filice in sight in the Daytona infield, even
when we were on evenly match bikes, and I certainly wouldn't have let
on here that I was so foolish as to run out of money while trying to
compete in a national AMA race series at the age of 51.
Sure glad I kept up my "I am perfect facade" and never admitted
anything like that!
Bob Nixon
> Bob Nixon wrote:
> > Thanks, ED but I did have this engine tuned on the rich side on a dyno
> > by a guy who's a two stroke expert in our area. He said he could have
> > gotten a few more HP more if he'd have gone one jet main jet size
> > smaller
>
> Are you sure the plug heat range wasn't too hot? What color are the plugs?
>
> --
> Ed Light
>
> Better World News TV Channel:http://realnews.com
>
>
> Iraq Veterans Against the War:http://ivaw.orghttp://couragetoresist.org
>
> Send spam to the FTC at
> Thanks, robots.
Nope. ED the plug range was about the coldest recommenced for this
bike (I live in hot Arizona) so starting and flooding is not a big
problem here and cold plugs are easier on pistons.
Bob..
Bob Nixon
OK,. OK, Tim but I wasn't one bad mouthing about "your woes", Harley
or not, for something you never did like you did to me due to a miss-
worded title. Just reading the 1st two paragraphs should have made
things perfectly clear to you. Plus all the PAST history I've written
about the same bike you once owned and raced. And no I don't expect
you to have a photographic memory but most the stuff about my dyno
runs and re-jetting has been posted in the last two months.
Bob..
Ed Light
>> Are you sure the plug heat range wasn't too hot? What color are the plugs?
>>
>> --
>> Ed Light
> Nope. ED the plug range was about the coldest recommenced for this
> bike (I live in hot Arizona) so starting and flooding is not a big
> problem here and cold plugs are easier on pistons.
It's still bugging me. Despite recommended heat ranges, the actual plugs
used should always be checked after a plug chop before venturing forth
with them.
Do you have the plugs, to check the color of the insulators under the
tips? That is, that started out as white porcelain? The color tells the
temperature. They should be chocolate brown. If they're white it was
probably bound to break, and needed colder plugs.
--
Ed Light
Better World News TV Channel:
http://realnews.com
Bring the Troops Home:
http://bringthemhomenow.org
http://antiwar.com
Iraq Veterans Against the War:
http://ivaw.org
http://couragetoresist.org
Send spam to the FTC at
sp...@uce.gov
Thanks, robots.
Bob Nixon
> Bob Nixon wrote:
> >> Are you sure the plug heat range wasn't too hot? What color are the plugs?
>
> >> --
> >> Ed Light
> > Nope. ED the plug range was about the coldest recommenced for this
> > bike (I live in hot Arizona) so starting and flooding is not a big
> > problem here and cold plugs are easier on pistons.
>
> It's still bugging me. Despite recommended heat ranges, the actual plugs
> used should always be checked after a plug chop before venturing forth
> with them.
>
> Do you have the plugs, to check the color of the insulators under the
> tips? That is, that started out as white porcelain? The color tells the
> temperature. They should be chocolate brown. If they're white it was
> probably bound to break, and needed colder plugs.
>
> --
> Ed Light
>
> Better World News TV Channel:http://realnews.com
>
>
> Iraq Veterans Against the War:http://ivaw.orghttp://couragetoresist.org
>
> Send spam to the FTC at
> Thanks, robots.
Ed did you read in my original message that I plan yo pull the head
off and take pictures then relay them online here?
Bob..
Bob Nixon
Thanks, Andy. I would have called you but you're farther away and I
thought you might be dirt-biking that morning.
Bob..
Bob Nixon
> actually I wonder what would be the best modern or semi-modern
> equivalent of RZ-350 in terms of handling, weight and power ...
Andy, that would be the SV-650-:)
Bob..
BrianNZ
Do you need to take the heads off to get the plugs out to have a look at
them?
Tim
> > when we were on evenly matched bikes, and I certainly wouldn't have let
> > on here that I was so foolish as to run out of money while trying to
> > compete in a national AMA race series at the age of 51.
>
> > Sure glad I kept up my "I am perfect facade" and never admitted
> > anything like that!
>
> OK,. OK, Tim but I wasn't one bad mouthing about "your woes", Harley
> or not, for something you never did like you did to me due to a miss-
> worded title.
Please show me where I bad mouthed you or your woes, Bob?
Or are you so twisted now that you think "Glad you weren't hurt" is
bad mouthing?
Quite frankly, my post was incredulous that you, knowing what you do,
would have been riding the bike if it was getting 65mpg. Since you
also quoted your SPEED in the title, I had NO INKLING and NO REASON to
suspect a typo; if I had ASSUMED a typo and been wrong, you would be
excoriating me now for THAT.
IOW, typing to you is a lose:lose proposition. Best of luck, and good
fortune to you, Bob.
Joey Tribiani
>
> Definitely not the "happy Bob" we were promised a few days ago, eh?
>Would you be if your bike blew up on you, Joey. Hell, most of your
>posts are responses to other's posts anyway or hardy one to chastise
>me.
>Bob..
this is your biggest problem, Bob. You get so angry that you must drop to
trying to belittle others to make yourself feel better... I didn't chastise
you, and you have a right to be upset at your bike, but being an asshole to
folks on the board because of it is childish. Demanding apologies for things
you misunderstood while claiming others didn't read well, is just a small
portion of your "normal" unhappy self...
Joey Tribiani
"AlF" <spamgrinde...@ggmail.com> wrote in message
news:4AF8F027...@ggmail.com...
>- I guess a
> decent motorcyclist :poke: should be able to catch it was a typo ...
> anyways ...
>
us mere mortals are only blessed with what is written...unless we read into
it and assume things, then we would be told to read what is written...<sigh>
Bob Nixon
OK, Tim I'll give you that one satisfaction of always being right
(except for your initial ass chewing ) The "glad you weren't hurt" was
nice both considering the text you wrote directly above that and my
detailed explanation in the message body. And Tim, I don't write posts
that kick people when they've fallen rather I'll go after the Hot Air
balloons but hey, that's my style.
Bob..
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
Heah, I never claimed to be "perfect". Just remember this was all
about a typo in the Subject line. Surely not good on my part and I do
admit to being overly defensive. OK, Joey?
Bob..
Bob Nixon
No Brian, but it will kill two birds with one stone. And it's just one
head like your F4i but much simpler and smaller or kind of like an old
Flathead four stroke parallel 180 degree twin with all the business
end below the head except the plug and combustion chamber & water
jacket.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280370.JPG
Note that this photo was from the original failure nearly 2 years ago.
Bob...
Steve Lusardi
Stop being mean...it makes you appear a fool, I have been building race bikes continuously since 1960 and I'm still doing it
....quite successfully, I might add. I will repeat, there is no such thing as dynamic compression ratio. There is however, an
observable increase in cylinder filling, due to those factors you mentioned, which does result in greater chamber pressures and
heat. When this temperature increase exceeds the flash point of the fuel, self ignition occurs(dieseling) and as the flame front
propagates across the combustion chamber it will collide with the spark generated flame front at which time, both chamber
temperature and chamber pressure spike.This temperature is considerably higher than the melting point of aluminum. Additionally,
this flame front collision is very loud and can easily can be heard., even above a screaming exhaust. It is unmistakable and
because of the thermal mass of the piston, several cycles are necessary to actually melt a piston. Once detected, there is ample
time to back off the throttle before piston failure occurs. Now I have no way of knowing how this engine was jetted, I wasn't
there, but I will tell you that with the elimination of leaded fuel, spark plug coloring no longer occurs. That light brown
coloring was lead bromide ash, which was used as a valve seat lubrication to prevent valve recession with iron valve seats. Since
spark coloration can no longer be used to guide the tuner, this feedback is now provided by wide-band O2 sensors, like the 5 wire
Bosch unit. So, if you really want to know what is going on, you need to use a Dyno Jet Commander or equivalent, otherwise you are
blind. Now this detonation event can be caused by excessive lube oil, poor fuel or most likely A/F ratio. Many others have also
given you this same advice. Defending your knowledge base when asking for advice is not productive. Now do your homework, go
change your pistons, polish up the chamber in the heads, use the correct heat range plug, check your oil to fuel ratio and use an
A/F meter/datalogger and find out what is really happening. I am sure the group would like to know. It will be both educational
and therapeutic.
Steve
"Bob Nixon..
1949 Whizzer
So, if you really want to know what is going on, you need to use a
Dyno Jet Commander or equivalent, otherwise you are
> blind. Now this detonation event can be caused by excessive lube oil, poor fuel or most likely A/F ratio.
Does Dynojet make a box for two strokes?
I think it was ~kurt that was asking if anybody knew how to build a
detonation sensor for his 125cc GP bike to avoid paying Honda $800 for
the factory equipment.
Who ever wrote about it said that crisply-tuned 2-strokes were allowed
a maximum of ~5 or 6 detonation events per lap.
The detonations occur whenever the rider rolls off the throttle
momentarily while setting up for a turn or if a slower rider get in
his way.
A question for Bob would be "how much part throttle riding had you
been doing before getting onto the freeway?"
Dyno tuning a 2-stroke engine allows power to be measured under steady
load conditions and the jetting optimized for power.
But a two-stroke engine has such a long intake tract from the
carburetor intake, through the crankcase and out the transfer ports
and down the exhaust port and back into the cylinder just before the
exhaust port closes that any change in throttle setting is disruptive
to the fuel/air mixture and the heat of the polluted/fresh charge that
rolling off the throttle causes the engine to start yakking and that
heats the poor little lightweight cast aluminum piston to a dangerous
point.
I have only melted holes in about three pistons that I can remember.
The tinkling sound of pre-ignition sounds like a loose valve, and pre-
ignition also makes an engine sound very sour when it starts.
When a four stroke engine starts backfiring out the exhaust, making
noises like it's duck season, that's time to park it and let it cool
off.
~kurt
>
> I think it was ~kurt that was asking if anybody knew how to build a
> detonation sensor for his 125cc GP bike to avoid paying Honda $800 for
> the factory equipment.
Sounds familiar. I'm definitely thinking of getting one.
> Who ever wrote about it said that crisply-tuned 2-strokes were allowed
> a maximum of ~5 or 6 detonation events per lap.
Yea, that is similar to what I had heard when getting read to take the
little bike out a while back.
- Kurt
Ed Light
>
> http://bigrex.net/pictures/Bob%27s_RZ-350/P4280370.JPG
> Note that this photo was from the original failure nearly 2 years ago.
The head's not the plugs. I just know what the plug's insulator should
look like.
--
Ed Light
Better World News TV Channel:
http://realnews.com
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http://couragetoresist.org
http://antiwar.com
Send spam to the FTC at
sp...@uce.gov
Thanks, robots.
Ed Light
> I wasn't there, but I will tell you that with the elimination of leaded
> fuel, spark plug coloring no longer occurs. That light brown coloring
> was lead bromide ash, which was used as a valve seat lubrication to
> prevent valve recession with iron valve seats. Since spark coloration
> can no longer be used to guide the tuner, this feedback is now provided
> by wide-band O2 sensors, like the 5 wire Bosch unit. So, if you really
> want to know what is going on, you need to use a Dyno Jet Commander or
How does the layman know when he's got plugs that are too hot? A
manufacturer can spec the wrong plugs, as I found out the hard way when
my Yamaha 180 blew, but that *was* way back in the '60s.
Joey Tribiani
>Heah, I never claimed to be "perfect". Just remember this was all
>about a typo in the Subject line. Surely not good on my part and I do
>admit to being overly defensive. OK, Joey?
>Bob..
it doesn't have to be "ok" with me. You needn't worry about being perfect
either, Bob. But jumping on Tim for his post was just you being you. It
wasn't over a typo, it was over ego. Yours this time, not his... If you
thought he was mistaken in what he read, clarification or asking a question
is much better than throwing a Bob fit...
1949 Whizzer
> How does the layman know when he's got plugs that are too hot? A
> manufacturer can spec the wrong plugs, as I found out the hard way when
> my Yamaha 180 blew, but that *was* way back in the '60s.
When your exhaust makes a loud "splork!" sound as you blip the
throttle, you should know that's caused by pre-ignition due to hot
plugs or lean mixture or advanced ignition.
Also, the poor engine *groans* as you ride along, it doesn't want to
run up to redline joyfully. Maybe you hear a tinkling sound like one
valve has a lot of clearance.
Indication that your engine is pre-igniting slightly is that there is
a bare patch of aluminum directly under the spark plug when you look
in the hole, and there are little black specks like pepper on the
insulator nose from melted carbon from the combustion chamber and
piston top.
The next step is shiny silver balls of aluminum deposited on the
insulator nose.
That's about the time the engine starts "shooting ducks" out the
exhaust, it sounds like a shotgun going off repeatedly.
Four strokes start smoking, and backfires light off the oil smoke...
After that, you get a holed piston...
But the tinkling and groaning and inability to rev smoothly should
have warned you long before you started melting a piston...
Bob Nixon
> On Nov 10, 12:43 pm, "Steve Lusardi" <stevenos...@lusardi.de> wrote:
>
> A question for Bob would be "how much part throttle riding had you
> been doing before getting onto the freeway?"
No Krusty, it was (I think) just a constant eating away, by that
poorly machined head on the same side, causing either hot spots and
subsequent more or less a constant detonation of say 20 pings per mile
of freeway traveled but I can't be sure until I pull the head off
later in the week. The second piston went because I just geared down
to forth at kept the tack at a constant 8000 RPM for over 15 miles at
>55MPH partial maybe 3/4 throttle so that other freeway traffic didn't
run over me. At that point that first piston failed it mattered more
to me that I get to a safe haven off the freeway at that point than
saving one side as re-boring the sleeve and replacing just one pistonr
to whomever gets this bike would imbalance the engine anyway (due to a
bigger piston on the one side).
[...] snip
Bob..
Bob Nixon
> Bob,
> Stop being mean...it makes you appear a fool, I have been building race bikes continuously since 1960 and I'm still doing it
> ....quite successfully, I might add. I will repeat, there is no such thing as dynamic compression ratio. There is however, an
> observable increase in cylinder filling, due to those factors you mentioned, which does result in greater chamber pressures and
> heat.
Come-on Steve it's clear that we just dealing with semantics & if
you'd have used the term BMEP or even cylinder filling actually "over
filing" in your original post then I might have been more receptive.
So we had a difference what is called semantics. OK, will you agree
that a naturally aspirated engine can and does have a volumetric
efficiencies greater than 100% or up to 120% on four stroke and over
150% on two stroke engines. The reason for the boost of the four
stroke is two fold or 1) the velocity of the falling intake charge is
great enough to actually compress the charge a bit before the valve
closure and 2) The piston's upward movement captures the over pressure
charge before the intake valve is fully closes. Also a third factor
might be that the cooling effect or say menthol alcohol moving into a
larger chamber than the valve opening has a natural cooling &
densening effect on the intake charge. This can all be verified using
BMEP pressure monitoring on "test engines" and YES computer real time
modeling. I'm not going to go back to 2 strokes and Kadden exhaust
principals as you should have picked that up before.
>When this temperature increase exceeds the flash point of the fuel, self ignition occurs(dieseling) and as the flame front
> propagates across the combustion chamber it will collide with the spark generated flame front at which time, both chamber
> temperature and chamber pressure spike.This temperature is considerably higher than the melting point of aluminum. Additionally,
> this flame front collision is very loud and can easily can be heard., even above a screaming exhaust
Not if it's not "pre-ignition" on a two stroke but a gradual
"detonation" or the dual flame front you alluded to that eats away
slowly at the light aluminum pistons. My new Shoe RF 900 helmet plus
good ear plugs is very quiet. Not to even mention at 64 years old my
ears are not what they once were. I actually feel insulted that you
would lecture me on the above as it's pretty elementary engine basics.
Same with the verbiage below this so I'm going to snip it. Christ you
wrote a whole paragraph on things I learned in HS auto shop likely
before you were born;)
Here's a couple of engine questions for you there Steve:
1) When titanium valves are used in an engine, what material must be
used in formation of the valve seats.
2) Do you know the difference between an internally scavenged two
stroke engine and an externally scavenged two stroke engine (usually
but not exclusive to Diesels) and if so please explain.
3) How does a dual fuel Diesel engine work. In detail.
4) what is the main difference between the design of Rolls Royce high
bypass turbofan and those built by the US GE/PW conglomerate.
Hint how many spools?
Thanks
Bob Nixon..
Ed Light
> The head's not the plugs. I just know what the plug's insulator should
> look like.
Now we know from another post that you can't read plugs because of
unleaded gas. Progress.
Ed Light
Thanks for the tutorial!
AlF
> >- I guess a
>> decent motorcyclist :poke: should be able to catch it was a typo ...
>> anyways ...
>>
>
> us mere mortals are only blessed with what is written...unless we read into
> it and assume things, then we would be told to read what is written...<sigh>
>
there is a skill called critical thinking too
Joey Tribiani
Here's a couple of engine questions for you there Steve:
1) When titanium valves are used in an engine, what material must be
used in formation of the valve seats.
2) Do you know the difference between an internally scavenged two
stroke engine and an externally scavenged two stroke engine (usually
but not exclusive to Diesels) and if so please explain.
3) How does a dual fuel Diesel engine work. In detail.
4) what is the main difference between the design of Rolls Royce high
bypass turbofan and those built by the US GE/PW conglomerate.
Hint how many spools?
Thanks
Bob Nixon..
_____________
LOL... is this chest thumping, "I's smarter than you is", or just being a
drama-queen?
Joey Tribiani
there's a skill called reading, it's pretty helpful... Critical thinking
would involve determining the significance of what is written... He found
Bob's "typo" very significant given the continued burning of pistons. He
wasn't the only one... I realize that you have a soft spot for Bob and know
him personally, but his fits of anger are just that, *his*...
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
Whats it to ya, Joey? If you know the answers then take a shot at
explaining -:)
Steve Lusardi
Very good question. The short answer is you don't, because coloring doesn't exist with unleaded fuel. The correct operating
temperature for spark plugs range between 700 to 1400 F. However in extreme (detonation) situations, aluminum deposition will be
visible on the ceramic insulator. Ultimately, only the use of a wide-band A/F sensor will suffice and that won't help plug
selection. Remember on a two stroke, cold is always better. If you sense a normal A/F ratio and you sense detonation, the plug
could be glow plugging causing pre-ignition.
Steve
"Ed Light" <nob...@nobody.there> wrote in message news:00f30daa$0$23390$c3e...@news.astraweb.com...
1949 Whizzer
Remember on a two stroke, cold is always better.
However, Gordon Jennings advised against using a cold spark plug to
mask a lean
condition...
I remember trying to use some of those really cold racing spark plugs
with the ground electrode buried inside the shell.
I had to start the engine and warm it up with hot plugs before
switching over to the cold plugs...
Andy Burnett
I can't tell for sure if you're done with the bike. It would be
understandable if you've had enough of this kind of "fun."
If you do decide to repair it after you cool off, here are a few
thoughts:
We can probably assume this is a detonation problem; I don't know what
else could hole the pistons like that. Whatever is causing the
detonation is not isolated to one cylinder.
It could be that the overall squish is too little. How has the squish
been measured in the past? If nobody has used a blob of clay to
confirm the squish, it would be a good thing to do.
Is there a temp gauge on the bike? I may have missed any references
to engine temp, but it would be an area of concern on an old engine
whose waterways may not be fully open.
Fuel flow problems are a possibility, but so are vacuum leaks in the
case. Have you had the case tested for leaks?
Finally, there is such a thing as a detonation counter. They tend to
be quite expensive, but there may be a lower cost option out there
somewhere. It's a piezo sensor that bolts to a flat spot on the head
and is connected to an LCD (usually) display that counts detonations.
It's a huge tuning aid and could make all the difference in diagnosing
the problem without having to hole another piston to know there's a
problem.
ab
1949 Whizzer
> Finally, there is such a thing as a detonation counter. They tend to
> be quite expensive, but there may be a lower cost option out there
> somewhere. It's a piezo sensor that bolts to a flat spot on the head
> and is connected to an LCD (usually) display that counts detonations.
> It's a huge tuning aid and could make all the difference in diagnosing
> the problem without having to hole another piston to know there's a
> problem.
I have no doubt that some rider who is also an electronics hobbyist
knows how to build a counter that would work with an automotive knock
sensor to run a counter on Bob's RZ...
My Ford T-bird had a knock sensor bolted to the intake manifold.
If it counted 5 detonations, the ECU retarded the ignition.
Unfortunately, that didn't help because the spark plugs were already
glow-plugging
because a failed oxygen sensor wasn't signalling the ECU to increase
the amount of fuel injected.
The engine continued to ping and "dieseled" when I turned the ignition
switch off.
Not understanding the problem, I installed spark plugs that were one
heat range cooler.
The engine no longer "dieseled" after the ignition switch was shut
off, but the car wouldn't pass a smog test because a lean mixture
won't burn completely and excess HC's get kicked out the tail pipe...
I was mystified by how there could be sufficient excess O2 in the
exhaust and the HC still be too high, but a really nice mechanic told
me what was happening and I installed a new O2 sensor myself.
Then the T-Bird passed the smog test and I went back to the correct
spark plugs.
Bob Nixon
> Bob,
>
> I can't tell for sure if you're done with the bike. It would be
> understandable if you've had enough of this kind of "fun."
Yes and it's going to run this old geezer into the poor house with
twice as much $$ expended on this bike alone than the 5200.OTD that I
paid for my very reliable 06 SV-650.
> If you do decide to repair it after you cool off, here are a few
> thoughts:
>
> We can probably assume this is a detonation problem; I don't know what
> else could hole the pistons like that. Whatever is causing the
> detonation is not isolated to one cylinder.
This my though as well. With the head being the culprit but I won't be
able to tell until I pull the head. Something I'm not looking forward
to doing as it involves a lot of moving the bike around in the garage
(coolant drainage) then removing plugs and finally the head. I don't
do much of my own wrenching anymore with just one leg and a weak
heart. However I will do it before weeks end just to see for myself
what the problem has been, all along.
> It could be that the overall squish is too little. How has the squish
> been measured in the past? If nobody has used a blob of clay to
> confirm the squish, it would be a good thing to do.
It hasn't at all, Andy. I wouldn't even know how to do it. I thought
that this was something done by design originally worked out on a
computer. But I do know the head was reworked from the very 1st
failure by this picture below:
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280370.JPG
And it was caused originally by this crack in the left cylinder wall
after a 120MPH run after which I rode the bike nearly 20 miles back to
my home on one cylinder on the freeway at say 55-60MPH.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280369.JPG
Andy, notice the crack above the exhaust port. possibly or maybe a
localized cooling jacket problem as it's directly above the hot
exhaust port.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4210368.JPG
Andy, second from the left is the left plug after the top left side of
the piston broke off hammering around inside. see piston damage below
and the right plug is the third from the left or -0- damage to the
right side of the engine when these problems 1st occurred two years
back.
http://bigrex.net/pictures/Bob%27s_RZ-350/P4280373.JPG
> Is there a temp gauge on the bike? I may have missed any references
Yes, it was in the high 50s Sunday morning so the temp gauge was dead
center or coolant temp about 180 degrees opening and closing with the
thermostat.
Two year back during the original failure the temp gauge was up around
200-210 but still below the hot red line of 220.
> to engine temp, but it would be an area of concern on an old engine
> whose waterways may not be fully open.
Andy, it's a 25 year old bike with low mileage, so it spent most of
it's life in some barn or similar until I got it.
> Fuel flow problems are a possibility, but so are vacuum leaks in the
> case. Have you had the case tested for leaks?
I don't think so especially this time around. The fuel petcock was in
the prime position and you can hear the case sucking good when you
crack it with a tad of open throttle. But I've never done a leak down
test or would I know how or the mechanics I've been dealing with.
You'd think it would leak by the rings in short order anyway.
> Finally, there is such a thing as a detonation counter. They tend to
> be quite expensive, but there may be a lower cost option out there
> somewhere. It's a piezo sensor that bolts to a flat spot on the head
> and is connected to an LCD (usually) display that counts detonations.
> It's a huge tuning aid and could make all the difference in diagnosing
> the problem without having to hole another piston to know there's a
> problem.
Andy, way too expensive for my budget. I've head $800.00 & up.
Thanks very much, Andy. Bob..
Joey Tribiani
>Whats it to ya, Joey? If you know the answers then take a shot at
>explaining -:)
The questions themselves are actually fairly easy ones. Fortunately I don't
measure my worth or penis size by quizing folks that disagree with me. You
usually do. so I must ask again, is this chest thumping, "I's smarter than
you is", or just being your usual drama-queen.... If you know the answer,
take a shot at answering.
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
>
> news:f321e513-b6a4-4ebe...@o10g2000yqa.googlegroups.com...
>
> >Whats it to ya, Joey? If you know the answers then take a shot at
> >explaining -:)
>
> The questions themselves are actually fairly easy ones. Fortunately I don't
Yes easy, so please by all means just answer the last one for me,
Joey.
> measure my worth or penis size by quizing folks that disagree with me. You
> usually do. so I must ask again, is this chest thumping, "I's smarter than
> you is", or just being your usual drama-queen.... If you know the answer,
> take a shot at answering.
You got me. It was plain old chest thumping.
BTW, I pulled the plug and took pictures for those who want to analyze
the condition. I'll post it in a separate thread.
Bob..
Ed Light
> On Nov 10, 11:17 pm, "Steve Lusardi" <stevenos...@lusardi.de> wrote:
>
> Remember on a two stroke, cold is always better.
>
> However, Gordon Jennings advised against using a cold spark plug to
> mask a lean
> condition...
I'd think if you found the fastest jet, it wouldn't be lean. Then, too,
are they still using main jets these days? No need to answer.
>
> I remember trying to use some of those really cold racing spark plugs
> with the ground electrode buried inside the shell.
>
> I had to start the engine and warm it up with hot plugs before
> switching over to the cold plugs...
That's just how my racing bike was. I lent it to a friend, and he went
out on the warm up plugs and locked it up.
Joey Tribiani
>Yes easy, so please by all means just answer the last one for me,
>Joey.
I guess you missed the part where I said I wouldn't be part of your game of
measuring penis size or worth on silly questions that are totally unrelated
to anything in this thread, or this group.
> You got me. It was plain old chest thumping.
>BTW, I pulled the plug and took pictures for those who want to analyze
>the condition. I'll post it in a separate thread.
>Bob..
I haven't seen the link posted, but I believe you know (and others have said
also) that it was a lean condition. It is obviously something common to both
cylinders and wasn't fixed by replacing the damaged parts from the previous
incidents. You already suspected lean condition and even took steps to
counter what you felt the problem was.(the vacuum fuel tap). I think you
may have eliminated that as the culprit at this time. Ever do a flow test to
see if the fuel tap was flowing enough? Ever consider tank venting problems
hindering the fuel flow on the interstate(tank building up enough vacuum to
overcome the head pressure)? It's likely to be a simple enough problem to
fix, but like many "easy fixes" they are not always easy to find...
Bob Nixon
> "Bob Nixon" <bigrex2...@yahoo.com> wrote in message
No, but on the fuel delivery thing you may recall I said that I
intentionally put the petcock in the prime or always on position when
riding on the freeway and I can say in that position the flow was very
good into a can without running. However the tank vent is a new and
possibly overlooked cause. Wouldn't it be a bitch if that was all that
was wrong. I'd feel like putting a gun in my mouth-:) I'll check it
out and thanks for the suggestion, Joey.
Bob..
AlF
>
> there's a skill called reading, it's pretty helpful... Critical thinking
> would involve determining the significance of what is written... He found
> Bob's "typo" very significant given the continued burning of pistons. He
> wasn't the only one... I realize that you have a soft spot for Bob and know
> him personally, but his fits of anger are just that, *his*...
>
I think you hit nail on the head. Indeed- knowing someone personally
opens for 90% of non verbal communication which we simply are missing
here. Thus we take posts in so different way.
For instance - what I can tell about your posting here. I rarely see
something original, for the most time you are on hunt for all kinds of
inconsequences, hypocrisy and other pathologies.
Still written communication is essential, especially these days - I
guess most of us are just using perhaps unconsciously all kinds of
forums , boards, groups as some sort of training ground.
Joey Tribiani
>. However the tank vent is a new and
>possibly overlooked cause. Wouldn't it be a bitch if that was all that
>was wrong. I'd feel like putting a gun in my mouth-:) I'll check it
>out and thanks for the suggestion, Joey.
when troubleshooting I like to do the brainstorming and then eliminate all
the simple things... I sure hope it's not a vent problem, you might be
grumpy, but we don't want you eating a lead pill....<wink>
Joey Tribiani
> Joey Tribiani wrote:
>
>>
>> there's a skill called reading, it's pretty helpful... Critical thinking
>> would involve determining the significance of what is written... He found
>> Bob's "typo" very significant given the continued burning of pistons. He
>> wasn't the only one... I realize that you have a soft spot for Bob and
>> know him personally, but his fits of anger are just that, *his*...
>
> I think you hit nail on the head. Indeed- knowing someone personally opens
> for 90% of non verbal communication which we simply are missing here. Thus
> we take posts in so different way.
I agree... Without knowing the "whole" person we can only judge by what we
read...
>
> For instance - what I can tell about your posting here. I rarely see
> something original, for the most time you are on hunt for all kinds of
> inconsequences, hypocrisy and other pathologies.
I can understand that... but, see above... I read it all, but not much of
the "normal" stuff here will get me to post, those will, though.
AlF
any update on your poor RZ?
Andy