700 Triple killing plugs...
Jeff
I have a 1998 Formula III with a 700 triple and MACH 1 triple pipes
and 3000kms.
Towards the end of the year it started to burn-up sparkplugs extremely
quick. Some times I would get 30kms other times 3kms out of new
plugs. I had the carbs done at the local dealer, added a new oil
injection cable and had that adjusted. The machine was a whole lot
faster but it still killed the sparkplugs after a 30 - 40km run.
Anyone have an ideas? I've tried various heat ranges of plugs and
found BR10ES to last the longest but the problem is still anoying and
expensive.
Wes 94ZR580
am only familiar with fouling plugs. What do the plugs look like? Are
they black and covered with wet, gooey crap? I would think that if it
was hot enough in the combustion chamber to burn-up a spark plug then
the piston would have melted first. If I remember correctly a BR10 plug
is cooler than a BR9 plug. If the motor was designed for a BR9 then the
BR10's would be more susceptible to fouling. What is the piston wash
like? Is the top of the piston mostly bare aluminium, or is it mostly
dry, black, carbon with bare aluminium spots by the exhaust and transfer
ports. The later is more what you want.
Fouling plugs is a result of too rich a mixture. It sounds like your
jetting was changed at the dealer and is now way too rich. Pull the
carbs and see what the main jet is and compare that to what you had in
there before. Stock jetting for a Formula III 700 will probably not work
because you have triple pipes, so you have to find the right set up for
your custom application.
Wes
94 ZR580
Wesley Thiessen
after?
charles stoyer
part but not the annoying part. Just sandblast the fouled plugs and reuse
them. Then move to a hotter plug.
But if you found BR10ES work best, these are cooler than BR9ES or BR8ES, so
burning sounds like it is your problem.
Maybe the mixture is too lean then?
Charles.
"Jeff" <je...@bonavista.net> wrote in message
news:6277cd89.03071...@posting.google.com...
Wesley Thiessen
not the symptom. JMHO.
Jim
(0.018"). This is per a service bulletin from Ski-Doo (1998 manuals
will recommend the BR10ES..). Your jetting should be the same as the
Mach 1 for whatever year pipes you have on it, if you need these, let
me know, and I can look it up in the Ski-Doo spec books.
I put a 1999 F III 700 engine in my sled, with my original '97 Mach 1
pipes, and used the jetting for a 1997 Mach 1.
What type of temperatures were you riding in when the plugs were
fouling? The factory jetting is set for 0 degrees C or -20 degrees F.
I have also found that using BR9EYA spark plugs on my sled helps with
fouling problems. I can easily go at least 1 season on one set of
plugs, but if I am riding when it's really warm out, I will foul out a
set every couple miles..
Hope this helps...
Jim
1997 Ski-Doo Mach 1
Sasquatch
you people do that? I change plugs every 2000 miles or so and they are not
fouled when I do. What this guy is talking about is burning up plugs. If
10's last longer than 9's it sounds like he is to lean not to rich. I'd say
take it to the dealer and have him check out the pistons.
"Jim" <jim_...@hotmail.com> wrote in message
news:ss9bhv0vlm4r565u3...@4ax.com...
Gary C
> The factory jetting is set for 0 degrees C or -20 degrees F.
O degrees C is freezing
100 degrees C is boiling, AFAIK
Wes 94ZR580
Jim
The factory jetting is set for 0 degrees F or -20 degrees C
I mixed the F and C up..
Sorry..
Jim
On Thu, 17 Jul 2003 09:01:49 -0600, Wes 94ZR580 <Xfw...@sasktel.net>
wrote:
Gary C
> I mixed the F and C up..
>
> Sorry..
>
> Jim
I wasn't trying to bust your balls, Jim.
I had trouble with that "new math", never mind the metric system!
But you have to admit, the above does look funny.
Just add the *U* and the *K* to your sentence, and well ....
MUHAHAHAHAHAHA!
Jeff
The plugs are definately burnt not fouled. They usually come out of
the machine white/grey. The jets are set to factory FIII specs (I
cant remember what that is now though) according to the dealer.
The temperatures I ride in arent extrememly cold, usually from -10 to
+3 (celcius). The machine has an electic temperature gauge too and it
never runs really hot. When I am riding it stays low but if I stop
and leave it running, the temperature does go up but not even close to
extreme. I would think it was normal.
The mechanic did say that the tops of my pistons were "Cleaned off."
I guess he means down to the aluminum with no carbon left. The
machine was better after getting it back from them with the new jets
and everything tuned up, but it did still ruin the plugs. I can feel
when it starts to happen and a few minutes later the skidoo loses all
its power.
How about oil? I havent been religiously using Bomabardier Brand like
they say you should. If I dont have any oil and I am at a gas station
I just take what they have on the shelf!
Wes Thiessen
either... hope you have no serious problem. You need to solve it before you
ride thats for sure. Take a look down you sparkplug holes and look for
damage to your pistons. Maybe you have a bad seal...that can cause it to
run lean. Are all cyls/plugs the same?
Doo oil is good., but I can't see this problem being related to oil at
all.... looks all fuel/air to me.
Good luck!
"Jeff" <je...@bonavista.net> wrote in message
news:6277cd89.03072...@posting.google.com...
Wes 94ZR580
"new plugs" David mentions for reading plugs are not brand new, fresh
out of the package plugs, but ones with 20 - 30 miles on them. They need
a few miles to 'take on a colour' before you can read them, or before
they can tell you anything.
Thanks for some more good info, David.
Wes
94 ZR580
David Courtney wrote:
>
> The spark plug gives you a "snapshot" of what was going on inside the
> engine at the moment (or very shortly before) you shut it off.
> In order to know whether you have the correct main jets by reading the
> spark plug, you have to ride it wide open throttle for as long as you feel
> safe/comfortable... then shut the engine off and coast to a stop. You can't
> idle back to the trailer or ride back to the house to pull the plugs.
> If you want to know whether you have the needle clip set at the right
> height, you have to run it at 1/2 or 3/4 throttle (after you're sure you
> have the correct main jets in it) and shut it off... coasting to a stop, and
> read the plugs on site.
> Looking at the plugs after the thing has lost power and quit running
> just tells you that it was running like crap before you shut it off...
> unless there is permanent evidence of detonation or perhaps anti-freeze
> contamination.
> "Clean" pistons come from running the engine rich, however you may be
> rich on the main jets and deathly lean on the needle... giving you a hot
> spot at perhaps 1/3 or 1/2 throttle.
> Another possibility is that you're clutched for the wrong rpm now that
> you have a different set of pipes. If you're forcing the engine to run
> closer to it's torque peak that what the jetting specs were based on... you
> can get extreme piston temperatures, detonation, spark plug overheating, all
> sorts of the things.
> Keep in mind that if your engine is supposed to be clutched to run at
> say 8,500 rpm... then there is really no way that it would ever normally run
> at 8,000 and wide open throttle for any length of time. So to run at 8,000
> rpm would normally require perhaps 7/8 throttle... letting in less air and
> possibly drawing more fuel (more vacuum) than 8,000 rpm at full throttle
> does.
> Being clutched for the incorrect rpm can lead to all sorts of problems
> that you wouldn't normally expect... because these engines are designed and
> tuned to work with the clutch to put out extremely large amounts of power
> for their size.
> Anyway, I would suggest you get the main jets sorted out first, then the
> needles (should check 1/2 and 3/4 throttle with dual taper needles) and
> finally sort out the idle speed and pilot settings. New plugs help
> tremendously when dialing the carbs in, because it's easier to see the
> changes.
> Good luck,
> David
>
> --
>
> "Jeff" <je...@bonavista.net> wrote in message
> news:6277cd89.03072...@posting.google.com...
Wes 94ZR580
The jets are set to factory FIII specs (I
> cant remember what that is now though) according to the dealer.
>
This just might be your problem! You probably should start with Mach I
jetting, not FIII jetting. You should expect much larger main jets, and
maybe even staggered jetting with the triple pipes. My guess is you may
have gone way too far over on the lean side, which has meant that
combustion temperatures have begun to fall. This probably the only
reason you didn't experience a lean burn down. I have no idea what the
right jetting should be, but you might be looking at 3 -4 sizes bigger
than you have right now.
Wes
94 ZR580
Jim
On 22 Jul 2003 10:17:00 -0700, je...@bonavista.net (Jeff) wrote:
>Hi, thanks for the replies.
>
>The plugs are definately burnt not fouled. They usually come out of
>the machine white/grey. The jets are set to factory FIII specs (I
>cant remember what that is now though) according to the dealer.
>
Do you know what year Mach the pipes came off from?? Your main jets
should be (based on year/machine that the pipe came from..):
99 FIII 700 -- 290
99 Mach 1 -- 300
98 FIII 700 -- 310-300-310
98 Mach 1 -- 300
97 Mach 1 -- 350
Based on what you have said, I would guess that you have a set of 1997
Mach 1 pipes on your motor.
I took my sled to a local sled mechanic shop (not an authorized
dealer..) and I told him that I put a 1999 FIII 700 motor in my sled,
and he re-jetted the carbs for that sled. He didn't realize that HE
SHOULD HAVE JETTED FOR A 1997 MACH 1.. My sled didn't burn down, but
I would burn the spark plugs exactly as you mention. Luckily when I
rode it, it was toward the end of the season, so it was about 30
degrees F out, and it wasn't too lean to seize the motor (mind you, a
motor I bought with less than 100 miles on it, and spent the last
month installing it, while we had a lot of nice snow every day, my
brother and friends would do circles around the garage while I was
working on mine..)
>The temperatures I ride in arent extrememly cold, usually from -10 to
>+3 (celcius). The machine has an electic temperature gauge too and it
>never runs really hot. When I am riding it stays low but if I stop
>and leave it running, the temperature does go up but not even close to
>extreme. I would think it was normal.
>
>The mechanic did say that the tops of my pistons were "Cleaned off."
>I guess he means down to the aluminum with no carbon left. The
>machine was better after getting it back from them with the new jets
>and everything tuned up, but it did still ruin the plugs. I can feel
>when it starts to happen and a few minutes later the skidoo loses all
>its power.
>
>How about oil? I havent been religiously using Bomabardier Brand like
>they say you should. If I dont have any oil and I am at a gas station
>I just take what they have on the shelf!
I ran the Ski-Doo XP-S oil since my sled was new, recently I just
switched to Klotz Synthetic.. I got sick of everyone complaining
about the smell from my oil, nobody would ride behind me. I always
fill up before I ride (a tank lasts me around 500+ miles), so I
haven't had to buy it anywhere yet, but it seems to always be
available a most gas stops/bars. I have used other oils in a pinch,
though...
Jim
