hey guys, i have a 93 ovation i've had issues with, i use it for ice fishing, sometimes it runs with no problems 4-5 miles each way, others like today i made it about a mile and it just shut down.
i've replaced all the fuel, oil and vacuum lines, cleaned the pump, check the tank filter and vent all seem ok. compression was good cold in the garage but i wonder if i'm loosing vacuum somewhere when it warms up.
Problem is it runs fine some trips. fuel pump wouldn't do that, well not a diaphram pump any how, carb seems nice and clean, when i pulled the fuel line off the carb it pumped fuel but i don't think it pumped like it should be. i want to check my other sled tomorrow.
i'm about ready to tear the motor down but i would be seriously pissed if that didn't fix the issue and it was something stupid. seriously, anyone got any good ideas? anyone got solid numbers i can check the vacuum or fuel pressure....damn i'm better with cars, lol.
i've replaced all the fuel, oil and vacuum lines, cleaned the pump, check the tank filter and vent all seem ok. compression was good cold in the garage but i wonder if i'm loosing vacuum somewhere when it warms up.
Problem is it runs fine some trips. fuel pump wouldn't do that, well not a diaphram pump any how, carb seems nice and clean, when i pulled the fuel line off the carb it pumped fuel but i don't think it pumped like it should be. i want to check my other sled tomorrow.
i'm about ready to tear the motor down but i would be seriously pissed if that didn't fix the issue and it was something stupid. seriously, anyone got any good ideas? anyone got solid numbers i can check the vacuum or fuel pressure....damn i'm better with cars, lol.
PZ 1
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- Joined
- Mar 12, 2005
- Messages
- 987
Don't tear the motor down - you need to find out what is causing the problem - fuel - elecrical.
What happens after it quits? Can it be restarted?
What happens when you raise the enrichener lever when it starts to cut out?
It could be an electrical component heating up and causing a short or open circuit. If the fuel system seems okay, check for spark after it quits.
What happens after it quits? Can it be restarted?
What happens when you raise the enrichener lever when it starts to cut out?
It could be an electrical component heating up and causing a short or open circuit. If the fuel system seems okay, check for spark after it quits.
sorry, my bad i forgot to mention , its a fuel issue, no doubt. plugs come out dry as a bone with a good tan color. theres gas in the line up to the carb and the carb is clean. i'm not sure if it could be a float issue, seems like the float is operating properly, there was gas in the bowl when i pulled the carb.
i just wonder if a gasket is leaking after the motor runs a bit and loose vacuum to operate the fuel pump.
i just wonder if a gasket is leaking after the motor runs a bit and loose vacuum to operate the fuel pump.
Is this the one you have listed for sale over on michigan-sportsman?
lol, no its not, this is my other one with the racks on it for my fishing gear, exact same sled though.
i just went and did some checking, fuel pump diaphram still looks good, suck and blow on the pulse line and it pumps and the check valves are working properly so i checked compression and vacuum on the engine. seems now i'm only showing a tad less than 90#'s....so i think its rebuild time.
vacuum gauge needle bounced up to 1 in Hg and down to zero, didn't bother checking the other sled after i saw the compression numbers. i'm still curious exactly what went. seemed to present its self with loss of vacuum to run the pump.
i just went and did some checking, fuel pump diaphram still looks good, suck and blow on the pulse line and it pumps and the check valves are working properly so i checked compression and vacuum on the engine. seems now i'm only showing a tad less than 90#'s....so i think its rebuild time.
vacuum gauge needle bounced up to 1 in Hg and down to zero, didn't bother checking the other sled after i saw the compression numbers. i'm still curious exactly what went. seemed to present its self with loss of vacuum to run the pump.
I rebuilt my ovation when I tossed the motor in it. It's got a little bog but sometimes it runs like mad. Those carbs can be a real bugger.
dnale said:
Throw that funky "Teikei" carburettor in the trash can and put in an ordinary Mikuni VM-32/34 instead.
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mine was just wore out, i didn't have any carb issues, sounds like something was amiss, i've cleaned and adjusted my carbs and have good looking plugs, this sled just has some miles on it. my other one is real strong off the line, darn near pull the skis up just no top end to it, 45 mph is all i get with my fat butt, lol.
piston skirts are tore up, looks like the jugs may need a light bore job, i'm gonna run the hone in there and see what exactly i got.
lasse, how you gonna drop a mikuni on there, when the gaskets are setup for a large oval?
whats the electical hookup about on the side of the carb, i seen the abbreviation in a thread but have no idea what its about.
piston skirts are tore up, looks like the jugs may need a light bore job, i'm gonna run the hone in there and see what exactly i got.
lasse, how you gonna drop a mikuni on there, when the gaskets are setup for a large oval?
whats the electical hookup about on the side of the carb, i seen the abbreviation in a thread but have no idea what its about.
limige said:
No problem...
Just use the intake manifold ( 2 ) from an scrapped ET-340 engine.
+ a carburetor flange ( 10 ) made to Mikuni VM-32/34 dimensions ( Kimpex part # 07-100-13 ).
+ a throttle cable ( Kimpex part # 05-138 ).
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after it quite it wouldn't fire, dry plugs, no gas. let it sit and it would start. thats how it started.
then it quite once, would start back up i tried to baby it but it would still quite again, then restarted and went like all heck and it stalled again, then wouldn't start even after 20-30 min. finally got a tow and on the way in i tried it and it started and ran the rest of the way.
this time ran great and quite, no gas as usual, gas to the carb just not pumping, wouldn't start and i got a tow in. checked compression and it was 80 & 85 lbs, tore it down and the skirts were pretty trashed. i've honed about .003 off the diameter and still got scratches in the walls.
bottom line is it lost vacuum to operate the pump when warm and finally just lost compression.
then it quite once, would start back up i tried to baby it but it would still quite again, then restarted and went like all heck and it stalled again, then wouldn't start even after 20-30 min. finally got a tow and on the way in i tried it and it started and ran the rest of the way.
this time ran great and quite, no gas as usual, gas to the carb just not pumping, wouldn't start and i got a tow in. checked compression and it was 80 & 85 lbs, tore it down and the skirts were pretty trashed. i've honed about .003 off the diameter and still got scratches in the walls.
bottom line is it lost vacuum to operate the pump when warm and finally just lost compression.
Anyone know torque specs for the head bolts? How about piston/wall clearance and ring gap?
Oh and stock bore diameter..
PZ 1
Member
- Joined
- Mar 12, 2005
- Messages
- 987
Manuals here- http://www.midwestmanuals.com/Snowmobiles/yamaha.htm
Check the oiling system on the sled before you run it.
Check the oiling system on the sled before you run it.
Piston/wall clearance : 0.040-0.045 mmlimige said:
Piston ring end gap : 0.35-0.55 mm
Bore : 60.00 mmlimige said:
Stroke : 59.60 mm
Displacement : 337 cc
limige said:
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