Cuyuna versus Rotax
Rawn
I understand the Rotax 277 is no longer available. I am considering the
AMW Cuyuna 460 F35 instead. Being new to all this I wonder if the Cuyuna
has a reliability history as good as the Rotax. I will be using it in
the FFP 505. Any input will be truly appreciated, thanks.
Greg Johnson
site it tells the spec on the engines but not the reliability history.
It might help you.
Greg Johnson
gre...@accessus.net
CometX
I had 4 engine failures with a Cuyuna 442 in fifty flyimg hours, and 10
engine failures with Rotax 447 in the next 200 hours. The reasons didn't
always have to do with "reliability"; causes included fuel problems,
clogged filter, broken electrical wire, etc. The point is, with 2-strokes,
you have to fly with your brain in gear at all times.
The old Cuyuna 442 had problems with cooling because the air blew straight
back through both cylinders, so the back one didn't get cooled as well. We
solved that by simply tuning it so that it wasn't running on the edge of a
meltdown. Also, the 442 was beefier and hence heavier than the Rotax.
The real problem was the old ignition timing, which was impossible to set
right. Electronic ignition should have completely cured that. Cuyuna also
used a Mikuni carb, vs a Bing for the Rotax. There were more arguments
about the relative merits of the carbs than of the engines. The carb is
REAL important.
I'm not familiar with how the Cuyuna has evolved, but AMW looks like it is
comitted to it.
BillyBobC
Actually, they make a single cylinder engine (230__) which is slightly
less powerful than the Rotax.
Well to correct a few things, its a cuyuna 430 (430 cc) with different
sub
designations if it was a pull or push setup.
Back in 1983 or so they came up with less fins on the front head to
take less heat away so as to balance the forced cooling front-to-back.
With two carbs you can have a slightly richer mixture on the rear
cylinder to cool it a bit more. (the 2SI 460-f has 2 carbs).
The mikuni carb is a carb and the engine, exhaust and carb have to
be matched to your UL and where and how high you fly. As he said
you MUST fly with your head while letting your heart enjoy the flight!
Back when in the early 1980's, I flew 100+ hours with no failures
whatsoever, but I ran it with a 40:1 mixture thus it would need
servicing sooner than 50:1. I religiously checked the plugs and
cleaned them!
Good Luck!!
--
*************************************************
COMMITTEE (n) - Only known form of animal with a
hundred bellies and NO brain.
(Heinlein)
*************************************************
Mark Smith
CometX wrote:
>
> I had 4 engine failures with a Cuyuna 442 in fifty flyimg hours, and 10
> engine failures with Rotax 447 in the next 200 hours. The reasons didn't
> always have to do with "reliability"; causes included fuel problems,
> clogged filter, broken electrical wire, etc. The point is, with 2-strokes,
> you have to fly with your brain in gear at all times.
>
> The old Cuyuna 442 had problems with cooling because the air blew straight
> back through both cylinders, so the back one didn't get cooled as well. We
> solved that by simply tuning it so that it wasn't running on the edge of a
> meltdown. Also, the 442 was beefier and hence heavier than the Rotax.
>
> The real problem was the old ignition timing, which was impossible to set
> right. Electronic ignition should have completely cured that. Cuyuna also
> used a Mikuni carb, vs a Bing for the Rotax. There were more arguments
> about the relative merits of the carbs than of the engines. The carb is
> REAL important.
>
> I'm not familiar with how the Cuyuna has evolved, but AMW looks like it is
> comitted to it.
Your failure history would likely be the worst I've ever heard of in my
twenty six years of ultralight flying.
You've had more than I've had counting the West Bends, Mc Culloughs, Mac
101's, Cuyunas and Rotaxs put together. As an avid flyer since before the
word ultralight was coined, I've got a thousand or so hours in weight
shift Quicks alone. My BFI and pleasure flying has added several more
thousand at least.
With the same ratio of outs to hours, I'd have had over two hundred
engine outs in my flying career.
If I was you, I'd quit whilst I was ahead !!
--
---------------------------------------------------------
Mark Smith tri...@comsource.net
Tri-State Kite Sales http://www.comsource.net/~trikite
1121 N. Locust St.
Mt. Vernon, IN 47620 812-838-6351
CometX
>Well to correct a few things, its a cuyuna 430 (430 cc)
Deja Vu all over again.
Your right, as it now comes back to me. The 430R was the pusher. The front
fins were cut out or down to get more air in. But as I remember, they
created hot-spots on the cylinder walls, causing scuffing in places, or so
some said.
CometX
>Your failure history would likely be the worst I've ever heard of in my
twenty six years of ultralight flying.
What you consider "worst" I consider average. Two of my Cuyuna engine-outs
were in my INSTRUCTORS plane. He used marine outboard-engine oil to mix
with the gas. I paid him $250 bucks to learn how to fly by "crow-hopping"
up and down the runway; zero dual-time. I never heard the word "stall"
mentioned until AFTER I solo'ed. The next year, two students were killed,
both on departure stalls (the runway was a little short, lots of trees, the
engine was small (1 cylinder) and the pilots might have been too eager to
pick up the nose as they saw the trees coming...). Both the deceased were
"real" licensed pilots. He shut down his school after the second death.
Lets see if I can recollect all my dingers:
CUYUNA:
1 - instructors (single seat) UL. Engine out on climbout. Cause not
found. My total logged flying time at that point was 15 minutes. Landed in
a farmer field safely.
2 - Throttle cable kinked and locked in 50%power on final approach. I
killed engine and stalled from about 20 feet, breaking a bunch of stuff.
Major damage, as wing upper wires snapped on impact (this was an MX).
3 - Engine lost power on climbout. Revved unevenly, surging up and down,
then quit. Landed safely in field adjacent to my farm.
4 - The next morning, engine started fine, so I took off again. Seemed to
lack power, but since I only wanted to fly it about 500 yards back to my
farm, I taxied up a hill, then took off downhill. Engine quit 30 seconds
later. I just missed a small forest and landed in a rough field, breaking
and bending a bunch of tubes. Never found the cause.
Rotax:
5 - Wanted to practice dead-stick landings. Took off, leveled off at abot
30 feet, then cut ignition. Learned then that nose has to be pointing down
first. UL stalled and dropped hard. Major damage and almost broken back.
6 - At 5,000 ft. engine quit suddenly. Landed OK in large rough field
populated by pumpkin-size rocks. Found a ground wire on the Rotax had
broken from vibration.
7 - Fixed wire from #6 above. Cleared out rocks, but underestimated
takeoff roll needed. Just as UL was clearing the ground, one wheel impacted
a rock partly buried in the ground, and spun the UL 180 degrees, thrashing
it. Had to truck it out in pieces.
8 - 9 - 10 -11 - on four consecutive flights, the Rotax quit 10 minutes
into the flight, only to work perfectly later. In each case I landed safely
in various farm fields. After much frustration, I found the problem: I had
installed a fuel connector into the fibreglass tank. The unit came with a
small integral wire mesh filter. The filter had corroded and collapsed.
After takeoff, the 10 minutes of flying stirred up the gunk around the
filter so that it became caked and shut off. After the landing, the gunk
would release its hold, thereby making the engine work perfect again. I l
earned a lot from that one.
12 - Early morning landing, dew on grass, brakes useless as a result.
Landed too hot, couldn't stop the UL, it slid down a hill and into my barn,
bending leading wing spar 45 degrees. Just missed getting a barn pole in
my face.
13 - Coming home on a cup of gas left in the tank (which I could see in
the transparent and overhead tank in my MX), I decided to make a tree-top
pass over my friend's farmhouse. As I banked the plane sharply into a tight
turn, the fuel intake became exposed to air and the engine died. Landed OK
but plowed into a corn field. Moderate damage.
14 - Last summer. Prop fell off at1,500 feet AGL. I had filed down the
shaft slightly with emery cloth becaust the aluminum hub tended to fuse to
the steel shaft. This left some play. In addition, I had the wrong size
bolt - a tad too long, so that even with a couple washers, it still didn't
grip the shaft tightly, but I reasoned that the prop bolt, probably an
AN-5, was so thick that it could not possibly shear off. Wrong. It took 5
years, but it did. Landed safely.
All these "anamolies" were in my Eipper MX. God, I love that plane. It is
simple, well behaved, forgiving, strong, easy to repair. It is truly my
pal, a living friend.
Finally,
15 - this is an airplane crash, but different. I bought a Phantom from a
rich guy near Pittsburgh. We loaded it onto my rented truck. I drove all
night back to my farm, arriving very late and tired. In the darkness, I
tried to unload the plane alone. The wing were folded back. The Phantom has
the engine overhead and a very narrow wheel base. which makes it top heavy
without a pilot in it. The truck was not on level ground. The plane tipped
off the ramp, flipped over sideways, and rolled down a hill. I nearly
cried. I just bought a Rotax 582 water cooled for it. It's going to be awesome.
Fly Safely
Paul
AAsberry
>What you consider "worst" I consider average.
>Lets see if I can recollect all my dingers:
Have you considered a ground-bound recreational pursuit. I bet all the
neighbors, livestock and stray dogs take cover when they hear so much as a
weed eater fire up over at your place!
Your record has to rate right up there with the Wright boys.
>Fly Safely
Wishful thinking?
Are you sure you want a bucket of hot water hanging there above you?
Being an inquisitive sort, I wondered where the bolt had come from that
just bounced off my helmet and disappeared below. A West Bend gas tank
hanging by the fuel line was not the answer I was looking for.
(Seems) Long ago and far away
Andy
Jack Chomley
com...@aol.com (CometX) wrote:
>>Your failure history would likely be the worst I've ever heard of in my
>twenty six years of ultralight flying.
dthe nose as they saw the trees coming...). Both the deceased were
>"real" licensed pilots. He shut down his school after the second death.
es" were in my Eipper MX. God, I love that plane. It is
>simple, well behaved, forgiving, strong, easy to repair. It is truly my
>pal, a living friend.
>Finally,
>15 - this is an airplane crash, but different. I bought a Phantom from a
>rich guy near Pittsburgh. We loaded it onto my rented truck. I drove all
>night back to my farm, arriving very late and tired. In the darkness, I
>tried to unload the plane alone. The wing were folded back. The Phantom has
>the engine overhead and a very narrow wheel base. which makes it top heavy
>without a pilot in it. The truck was not on level ground. The plane tipped
>off the ramp, flipped over sideways, and rolled down a hill. I nearly
>cried. I just bought a Rotax 582 water cooled for it. It's going to be awesome.
>Fly Safely
>Paul
Large snippage> etc
I want you as the pilot on my next 747 Jumbo trip, seems the damn
wings could fall off and you would find a way to land it safely!
Regards,
Jack Chomley (Australia)
CometX
>I want you as the pilot on my next 747 Jumbo trip, seems the damn
>wings could fall off and you would find a way to land it safely!
>
since they emphasize aggressive reaction: get off your ass and deal with
the problem. Worst was the engine-out at 5,000. I started to get chest
pains and heart arrythmia, I guess from the excitement. I thought "great,
this thing is dropping, and I'm having a goddam heart attack." I started to
do "om" chanting to relax; at that altitude you got time. The main thing
is: you have to have your brain in gear. Know your priorities, pick a spot,
and stick to it. Watch for wires. Set up your approach, keep your speed
above stall and slide it in.
Ultimately, UL's are safer in an engine-out than "real" planes. They need
less landing room, have less mass and low stall speeds, which translates
into lower-force impact. You don't walk away from most "real" plane
dead-sticks. Every landing by a hang-glider rider is a dead-stick landing,
yet they do it safely.
Batjac
> Lets see if I can recollect all my dingers:
> All these "anamolies" were in my Eipper MX. God, I love that plane. It is
> simple, well behaved, forgiving, strong, easy to repair. It is truly my
> pal, a living friend.
>
> Fly Safely
> Paul
Man,
It's because of morons like you that I spend hours trying to explain to
everyone who looks at my Challenger II or hears about a plane crash that
homebuilts and ultralights are actuall SAFE!
Maybe two or three of your mentioned outages I could accept, but the
majority were just stupidity. Don't blame someone else because he was
an instructor. YOU paid him for the privilage of not flying. When I
learned to fly I asked LOTS of people who in the area was a safe,
responsible instructor. And practicing engine outs without proper
altitude and plane attitude? Didn't you talk to anyone (namely, the
aircraft manufacturer/dealer) about how to safely go about it? Read a
book, watch a video, or see any of the hundreds of magazine articles on
emergency training.
As for an engine quitting for unknown reasons, and then seeming to run
fine afterwards so go ahead and fly it anyway, that's asking for death.
STAY ON THE GROUND!
Sorry if I seem harsh, but in flying more than any other pursuit, the
law of natural selection (i.e. too dumb to live) never sleeps...
CometX
>>I spend hours trying to explain to everyone who looks at my >>Challenger
II or hears about a plane crash that homebuilts and >>ultralights are
actuall SAFE!
I neglected to respond to this particular statement in my first reply.
My reply might hopefully save an innocent person's life.
It is misleading of you to equate the safety of homebuilts to ultralights,
as your statement does. Homebuilts are registered aircrafts which are built
to FAA standards. Ultralights are not.
More importantly, I'm concerned that you have a 2-place Challenger. How
long will it be before you sucker a non-flying civilian into taking a
joyride with you, and then end up with dirt in your teeth, and your
passenger possibly injured or worse. A 2-place joyride is a great way to
impress Bobbi-Jo with your macho skills and help with getting her panties
off, but you're lying to her when you say that UL flying is safe. You know
and I know that's it not true. I have not met a SINGLE UL pilot flying more
than 50 hours who has not had an engine failure. How can you call that SAFE??
No, UL flying is NOT safe. It is a calculated risk which some of us
willingly accept, and should not dupe civilians into risking without
informed consent.
Fly Safe
CometX
CometX
>>>Don't blame someone else because he was an instructor.
I never blamed my instructor, except to say that some engine-outs were in
his plane.
I take full responsibility for some of the items: dropped prop, etc. Thats
pure laziness on my part.
Some, not all, engine outs are another story. Engine quits. I fiddle with
it by changing plugs, etc. Now it runs fine. A logical person has to assume
that it's now OK. Nee?
Stop pulling your chain: the Web is full of stories of UL emergencies,
Fillipaldi being the latest.. You make it sound like I'm the only one.
Difference is that I EXPECT emergencies, am prepared for them, and have
reacted competently when they happened. Maybe you don't have as much faith
in your flying skills as I do in mine.
Fly safe
CometX
Stuart Parker
>I have not met a SINGLE UL pilot flying more than 50 hours who has not had
an engine failure
You've met one now. Actually I'm married, but I gues I still count.
Mark Smith
Well, I'm single too and haven't had an engine out in the last four weeks
which was about fifty hours. Haven't had one for several years either.
Had more than my share back in the west bend and yamaha days though !
Last real problem I had was a broken crank in a 503. Flew it back and
landed with an exceptional shudder in the driveline somewhere.
AMKipple
In article <34268B...@comsource.net>, Mark Smith
<tri...@comsource.net> writes:
>
>Stuart Parker wrote:
>>
>> >I have not met a SINGLE UL pilot flying more than 50 hours who has not had
>> an engine failure
>>
>> You've met one now. Actually I'm married, but I gues I still count.
>
>
>Well, I'm single too and haven't had an engine out in the last four weeks
>which was about fifty hours. Haven't had one for several years either.
>
>
Make it two. I have flown from 1986 thru 1991 and then got out for a
while. Flew Rotax and Kawasaki. Never had one fail, never had one quit in
the air for any reason.
Al Kipple
ROTOPUP
> Homebuilts are registered aircrafts which are built
>to FAA standards.
Well, they may be registered but that doesn't mean they are built to FAA
standards. It isn't required...and many aren't.
Ron Natalie
ROTOPUP wrote:
> Well, they may be registered but that doesn't mean they are built to
> FAA standards. It isn't required...and many aren't.
Well, they are built to some standard, maybe not the same as
a conventional aircraft, but there are regulations that still
apply and they do have an inspection as part of the certification
requirements.
Your Part 103 ship isn't even guaranteed to be looked at by
someone who has seen an aircraft before.
Adam Morrison
I would say that you haven't talked to very many SINGLE UL pilots if
none of them have more than 50 hrs. without an engine out. I personally
have over 250 hrs in an MX, with a Cayuna (MODEL 440) and have only had
one forced landing. This wasn't an engine out either.
Lester Morrison
I have no problem with Cuyuna engines. For me they are as reliable as
any other engine that is taken care of. I wouldn't want to take off in a
plane of any kind that hasn't been checked over closely. Sounds like all
of your so called crashes were your own fault.
ROTOPUP
>Your Part 103 ship isn't even guaranteed to be looked at by
>someone who has seen an aircraft before.
Actually you are correct.....but an Experimental "Aircraft" DOES NOT have
to comply with much of anything concerning proper design.........
If you, as the builder, want to try and fly a tree trunk with a lawn mower
engine, you can be issued a registration # and an "airworthiness?"
certificate to "Try" to fly it.....even if the inspector doesn't think it
will fly. The inspection primarily has to do with verification of proper
Placards, markings, paperwork, registration and that the craft is amateur
built and meets the 51% rule; and to issue operation limitations for the
initial flight hours. It is not necessarily an airworthiness judgement at all.
Another thing to consider is that many Ultralight aircraft already have
"Experimental" versions of the exact same craft.....just more options that
make them too heavy for part 103. That doesn'tmake them more airworthy,
does it?
Ronald G. Blaylock
CometX (com...@aol.com) wrote:
}} >>I spend hours trying to explain to everyone who looks at my >>Challenger
}} II or hears about a plane crash that homebuilts and >>ultralights are
}} actuall SAFE!
}}
}} I neglected to respond to this particular statement in my first reply.
}} My reply might hopefully save an innocent person's life.
}}
}} It is misleading of you to equate the safety of homebuilts to ultralights,
}} to FAA standards. Ultralights are not.
Two what extent do you believe ultralights are not built to FAA standards?
They do not have to be, that is true, but do not make a flat statement that they are not. A lot of ultralights are registered, with "N" numbers and have met the FAA standards.
By the way, ultralights are almost always "homebuilt." Very few are factory assembled.
Ron B.
}}
}} More importantly, I'm concerned that you have a 2-place Challenger. How
}} long will it be before you sucker a non-flying civilian into taking a
}} joyride with you, and then end up with dirt in your teeth, and your
}} passenger possibly injured or worse. A 2-place joyride is a great way to
}} impress Bobbi-Jo with your macho skills and help with getting her panties
}} off, but you're lying to her when you say that UL flying is safe. You know
}} and I know that's it not true. I have not met a SINGLE UL pilot flying more
}} than 50 hours who has not had an engine failure. How can you call that SAFE??
}}
}} No, UL flying is NOT safe. It is a calculated risk which some of us
}} willingly accept, and should not dupe civilians into risking without
}} informed consent.
}}
}} Fly Safe
}} CometX
}}
}}
--
-----------------------------------------------------------------------
Ron Blaylock - AMSC USN (retired)
TO REPLY change the 'rgbsr' in the 'reply to' address to 'ron.b'
< ro...@cheerful.com > Living in San Jose, California
< rbla...@mail.arc.nasa.gov > Flying from Lodi, California
-----------------------------------------------------------------------
TWO4ULS
The last message sure didn't have anything to do with cuyuna vs rotax .
Lets keep with the program ,lets not get lazy and start a new subject.
