I have a 1980 Ski Doo Citation SS and it won't idle?

The motor is a 377 Rotax engine, with twin Mikuni Carburetors. The one carb on the clutch side will often backfire, and I can't get the motor to run for longer than like a minute. I changed all the fuel lines to make sure there were no leaks for air and that its running an enclosed circuit. Also the motor will compress 150 pounds on one side and 135 on the other.



If you have any suggestions, let me know!



ThanksI have a 1980 Ski Doo Citation SS and it won't idle?
Check the diaphragm fuel pump pressure and the crankcase impulse pressure line going into the fuel pump and the two fuel pressure lines going out to the carburetors. I'd have a new diaphragm kit inside the fuel pump quicker than snot. Are the rubber adapters between the engine and carburetors in good shape? Is the fuel filter and line to the bottom of the fuel tank in good shape? Remove the fuel filter and gas-cap and blow back inside the tank.

Make darn sure the gas-cap vent hole isn't plugged. Check the fuel floats and make sure both pilot jets are clear and clean.Check the carburetor air screw adjustments. As the air screws are turned clockwise the idle fuel mixture is made richer.

Hook an inductive timing light clamp to one of the spark plug wires and a car battery. Make syre the timing light is still flashing as the engine starts to quit. You may have a CDI ignition problem shutting off the engine.I have a 1980 Ski Doo Citation SS and it won't idle?
Low compression may be caused by worn compression rings on your pistons. But sometimes it may because of the sparkplugs if they are tightened down correctly. The fuel air mixture can sometimes escape thru the threads if the spark plugs arent tightened down correctly. Misfire can be caused from no spark to cylinders or fuel delivery or fuel pressure problems. But as a start you may want to check spark plugs.I have a 1980 Ski Doo Citation SS and it won't idle?
check and clean pilot jet. the wee little one.



those sleds were bad for, ignition box problems.



check for main jet sizes. my 1981 436cc liquid (9500blizzard) was 300/330 stock

meaning one side has bigger mainjet size.



my air cooled 340 yamaha runs best with #8 plug one side, #7 plug other side.

...fan side runs cooler.......yap it works.



I'd do a tear down and clean the cylinders and pistons. hone and new rings

...check your plug wires...and boots. NGKs look good



2 ramp roller clutch,, good luck