Hellow,
We have already 2 years a problem with our Suzuki DT 55 2-stroke engine build in 1985.
At full throttle the engine runs fine and powerfull but after +/- 30 seconds the power / rev. drops down to a lower level (like it runs on 2 - 2 1/2 cylinder). When I release the accelerator to a lower level (1/2 throttle) for 30 seconds and gives full throttle again, it runs fine again for 10 seconds and again the power loss.
When I run the engine at only 1/2 speed, it runs fine for a whole day.
When I run the engine at 3/4 speed, it runs fine for some minutes, but after that it starts pendling between the normal rev./power and lower rev./power. (like it is digital controlled )
When I give full throttle, and keeps full throttle, even when the rev./power is going down, after a minute the power goes more down until it almost reaches the idle rev. speed.
The spark plugs and cables are replaced already, the carbs are cleaned several times and look very good, the fuel ball (hand pump) is hard and pushing it during the problems wouln't help, the fuel tank and lines and filter are clean.
During the "problem period" all spark plugs gives a powerfull spark.
Should it be an electrical problem? (ignition coil / CDI unit?)
The cooling water coming out was nice warm (could hold my hand under it without burning it), so I don't think it was overheated.
What I have seen is air bubles in the oil injection hoses (but always still oil in the lines) This air is not from the oil pump but from the cilinders. I guess this is normal, but is it really normal?
I hope someone haves a good advice for us, We can replace the ignition coils and the CDI unit without further testing, but when it wouln't fix the problem, whe have spend a lot of money for nothing
We have already 2 years a problem with our Suzuki DT 55 2-stroke engine build in 1985.
At full throttle the engine runs fine and powerfull but after +/- 30 seconds the power / rev. drops down to a lower level (like it runs on 2 - 2 1/2 cylinder). When I release the accelerator to a lower level (1/2 throttle) for 30 seconds and gives full throttle again, it runs fine again for 10 seconds and again the power loss.
When I run the engine at only 1/2 speed, it runs fine for a whole day.
When I run the engine at 3/4 speed, it runs fine for some minutes, but after that it starts pendling between the normal rev./power and lower rev./power. (like it is digital controlled )
When I give full throttle, and keeps full throttle, even when the rev./power is going down, after a minute the power goes more down until it almost reaches the idle rev. speed.
The spark plugs and cables are replaced already, the carbs are cleaned several times and look very good, the fuel ball (hand pump) is hard and pushing it during the problems wouln't help, the fuel tank and lines and filter are clean.
During the "problem period" all spark plugs gives a powerfull spark.
Should it be an electrical problem? (ignition coil / CDI unit?)
The cooling water coming out was nice warm (could hold my hand under it without burning it), so I don't think it was overheated.
What I have seen is air bubles in the oil injection hoses (but always still oil in the lines) This air is not from the oil pump but from the cilinders. I guess this is normal, but is it really normal?
I hope someone haves a good advice for us, We can replace the ignition coils and the CDI unit without further testing, but when it wouln't fix the problem, whe have spend a lot of money for nothing