89 ovation having hard time starting and running

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Poleclimber84

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Joined
Oct 14, 2015
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12
Location
Grimsby ontario
Hi everyone, Bought a 89 ovation at the begining of the season and noticed that machine would bog down around 5/8 to 3/4 throttle. Took the carb apart and cleaned idle and main jets,floats and needle and seat. TORS is disconnect, changed the fuel pump fuel filter and ignition coil as well as spark plug caps. Machines has half descent compression with 125 on the pto side and 120 on the mag side. Machine does not want to run at all now. Can anyone HELP???
 

did you make sure all the carb passages are clean as well?

does it fire if you put gas in the cylinders?
 
Clutches are good. Spark plugs are always flooded and very clear almost like they are not getting any oil and it seems like the machine is always flooding
 
almost sounds like a bad fuel pump to me filling the bottom end through the pulse line if it is hooked up correctly. try the old pump again for fun after it sits disconnected from the motor for a couple of days to air out all the fuel in the bottom end.
 
That's a good thought only problem is I the fuel pump is new so you think it would do that? And I don't have the old one. Maybe if I disconnect the pulse line from the crank case and try starting the sled I will see if gas is coming out of the pulse line. What would you recommend the air screw be set to? Are they the ones that sit on top of the carb?
 
Its hard to test these motors with the ol' starting fluid trick so pop off the clutch, the flywheel and check for an oily residue around the seal.
 
If they have never been changed the crank seals are 27 years old. A two stroke is just an air pump with fuel added to the air flow and a timed spark plug to keep it pumping on it's own by burning that fuel. The crank seals seal the pumping chamber (crankcase) so the piston and it's ports can do their job of pumping air. Try priming and getting a water pump to pump water with leaky seals (not easy).

Now think of a water pump that was new 27 years ago and at most used on occasion 3 or 4 months out of a year. If it was having issues pumping would you suspect seals?

These Yamaha's are not prone to seal issues (they used good ones when they were built) but after nearly thirty years they are due for replacement. Even if it still runs good.

opsled
 
If the needle and seat were wore out, you would have a crank case full of gas. Only bore the cylinders if you ABSOLUTELY need to. The only reason to bore a two stroke is to bring the bore and piston clearance back to spec. There is no hp gains to be had by boring a stock cylinder .25,.50,1.0,or 1.5mm over unless the bore is out of wack. You have to increase the bore ALOT to (big bore) to see any gains and you would have to re-sleeve with a custom sleeve to do it. Not worth it on a little Ovulation 340.
 
like throttle junkie said and Opsled ....replace the crank seals they are way past needing to be done .....hard starting is most likely due to the seals, but stuck rings low compression or even a bad carb can be a issue which i will get into later .......but for now pull the motor and reseal it and while it is apart new rings should be installed
 
Good evening gentlemen it's the owner of the nightmare ovation. So I ordered a gasket set for the motor and I have the primary clutch off the machine and for sum reason I can not figure where the crank seal gasket is would anyone have a pic of this motor in a microfiche drawing
 
The crank seal is the rubber donut around the crank shaft. You need to pull off the flywheel, stator, fan housing, engine plate and pull the 12 or so bolts off the bottom half of the motor to replace them,
 
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