Yamaha 200 trouble

[oktrikefanatic]

I have a 1983 ytm200 that i got running for cheap. Soon after i was going down our driveway after downshifting and it dies. It has compression spark and you can feel exhaust coming out of the exhaust pipe. But I cannot get it to start even with ether. Also when you hold the throttle wide open and then try to pull it the motor wont budge,its like it locks it up somehow. It pulls just fine otherwise. Another thing is my spark plug was covered in oil. I cleaned it up but still no start.

[350for350]

Did you check the compression after it quit running? If not, maybe something is holding a valve open. Have you checked the flywheel key to see if it's in good shape? Those are just a couple of wild guesses.

[El Camexican]

Is the spark plug covered in wet clear oil, or burnt sooty oil?

[oktrikefanatic]

Is the spark plug covered in wet clear oil, or burnt sooty oil?

Wet clear oil

[El Camexican]

Wet clear oil

Ok, at the risk of being way off (given you said you were using ether) have you removed the air box cover and filter? I ask because the engine vent on that trike is attached to the intake assembly and if you tip the trike on its side, or upside down, oil flows into the air box. The only way to get it out is to remove the crimped plastic plug on the bottom of the air box. That’s the only thing I can think of that would give you clear oil on your plug and not mean that you’ve destroyed your engine. Any chance that your engine is overfilled with oil?

The part about not being able to turn your engine over when the throttle is opened doesn’t make any sense. I suppose if you had a bunch of oil getting in there it could be hydraulicing on the compression stroke, but the carb has nothing to do with that.

If my hunch about the oil inside your combustion chamber originating through the airbox is correct, then you’re going to need to drain and clean up your air box, remove your air filter, Wipe up as much oil as you can, remove the spark plug, pour a teaspoon of gas in the plug hole, Pull it over a few times, put a brand new spark plug in it and try to fire it up.

If there’s no oil in your air box then my next guess is that you broke a ring.

[oktrikefanatic]

Ok, at the risk of being way off (given you said you were using ether) have you removed the air box cover and filter? I ask because the engine vent on that trike is attached to the intake assembly and if you tip the trike on its side, or upside down, oil flows into the air box. The only way to get it out is to remove the crimped plastic plug on the bottom of the air box. That’s the only thing I can think of that would give you clear oil on your plug and not mean that you’ve destroyed your engine. Any chance that your engine is overfilled with oil?

The part about not being able to turn your engine over when the throttle is opened doesn’t make any sense. I suppose if you had a bunch of oil getting in there it could be hydraulicing on the compression stroke, but the carb has nothing to do with that.

If my hunch about the oil inside your combustion chamber originating through the airbox is correct, then you’re going to need to drain and clean up your air box, remove your air filter, Wipe up as much oil ias you can, remove the spark plug, pour a teaspoon of gas in the plug hole, Pull it over a few times, put a brand new spark plug in it and try to fire it up.

If there’s no oil in your air box then my next guess is that you broke a ring.

My airbox doesnt have oil in it and the plug on the bottom is missing, but the airfilter.The oil is right at full. I did take my exhaust and carb of and both valves are moving when i crank it over. Ok also do you know if a mikuni vm26 would work on it know the original is a vm 22.

[El Camexican]

My airbox doesnt have oil in it and the plug on the bottom is missing, but the airfilter.The oil is right at full. I did take my exhaust and carb of and both valves are moving when i crank it over. Ok also do you know if a mikuni vm26 would work on it know the original is a vm 22.

Is your manifold bolted to the cylinder and then the carburetor attached with a hose clamp, or do you have the carburetor with the two bolt flange that bolts to the rubber manifold? The first 200’s came with the clamp style carb and then got updated to the bolt on flange. Both carbs were proprietary as far as I know, but the newer style flanged type can be put on the older 200 as long as you use the newer manifold from a 200 or 225. If you want to try another carb it will probably require a custom manifold. You can try to find a carb from a 225, they were slightly larger, but the manifold I.D.’s are the same, so don’t expect any major gains.

You say the oil is at “full”. Do you mean on the dip stick, or to the top of the filler hole? (Sorry, but I have to ask given what you say about oil in the cylinder and not being able to pull it over).

Something else, do you have a manual? If not, just an FYI, to check oil level on that engine you remove the dip stick, wipe it off and drop it back into the hole WITHOUT screwing it back in, and them pull it back out to look at the level.

[oktrikefanatic]

Is your manifold bolted to the cylinder and then the carburetor attached with a hose clamp, or do you have the carburetor with the two bolt flange that bolts to the rubber manifold? The first 200’s came with the clamp style carb and then got updated to the bolt on flange. Both carbs were proprietary as far as I know, but the newer style flanged type can be put on the older 200 as long as you use the newer manifold from a 200 or 225. If you want to try another carb it will probably require a custom manifold. You can try to find a carb from a 225, they were slightly larger, but the manifold I.D.’s are the same, so don’t expect any major gains.

You say the oil is at “full”. Do you mean on the dip stick, or to the top of the filler hole? (Sorry, but I have to ask given what you say about oil in the cylinder and not being able to pull it over).

Something else, do you have a manual? If not, just an FYI, to check oil level on that engine you remove the dip stick, wipe it off and drop it back into the hole WITHOUT screwing it back in, and them pull it back out to look at the level.

The original carb had the clamp on manifold, but right now i have a chinese carb and a bolt on manifold which i want to get rid of because my air box hose dont line up very well with it. The oil is right on the full mark on the dipstick without screwing it in. Could popping wheelies cause oil to go into the cylinder? I just want a decent carb because the chinese one is trash. As long as the trike is turned off fuel will just dump out of the overflow, but as soon as you start it, it quits. I think fuel is getting past my needle valve

[El Camexican]

No, wheelies won’t do that.

Sounds like you need a carb rebuild and a top end inspection.

[oktrikefanatic]

No, wheelies won’t do that.

Sounds like you need a carb rebuild and a top end inspection.

Ok i guess ill tear into it thanks for the help