[slicnic]

ok so i think my bike has the symptoms of a right hand crank seal failing as ive had it happen before,im getting a bit of oil in the airbox through the breather tube and it seems the eng oil is filling slightly higher with the trans oil when its hot but after it cools the levels seem to go back to to normal, but i cant work out why after the engine is warm it starts to cough and splutter around quarter throttle but before that itl start and run fine. i even tried disconnecting the crank breather tube from the airbox because i thought maybe the oil going into the carb was causing it to run sick but it made no difference. ?? i just dont want to start stripping it down till im positive whats causing the weird symptoms

[Leardriver]

Airbox in the breather tube isn't an absolutely positive sign of anything but engine oil overfilled, or the bike laying on it's side after a crash. Yes, trans oil migrating over to the engine side could give that symptom.

But, we should make sure. You have to measure the oil that comes out of the engine and trans drains. It is possible to have a little leak rather than a gusher. It may take 2-3 drains and fills to verify.

A crank seal isn't a terrible repair, but cold parts in the winter would make me want to be pretty sure that was the problem first.

[Back2-2]

If you are seeing rising oil level on the engine side and the bike is running like you have a fueling issue [flooding] by your description-
You could be getting excess fuel into the engine oil causing the rise. The fuel then evaporates after sitting from the engine heat.
Check the spark plug, If it's oily or fuel fouled that can give you some direction.
If you are quite sure you have a crank seal leak - a pressure check would be in order to verify.

[slicnic]

i warmed the engine then stopped it and waited 5 mins to check it and it seemed very high but then after checking it again over night the level was back to normal could it be equalizing after sitting for a while?. i read somewhere about the stator pickup having filings on it (possibly coming from a stuffed seal) that could cause the engine stutter at revs? does this sound possible? just dont want to start pulling everything apart with no idea where the problem is , though i think that may be the onlyway to figure it out i pulled the plug and it was not oily and was the nice tan colour that suggests good jetting and it is starting very easy.

[Back2-2]

If the plug is nice tan as you described then rule out my idea of flooding. Ignition, carburetor or air leaks on intake system. Wires to coil, plug lead, grounds for ignition are places to check. Air boots and manifold for air leaks. I really do not think you have a seal leaking. The oil expands when hot and goes back to the original level when cool. The clean spark plug tells you that nothing is being consumed - oil or coolant. Ignition or carb is where I would be investigating,

[slicnic]

ok so i think ive solved it, took out the stator and had a mechanic test it and he said it was cactus so i think that would explain the spluttering , will have to wait n see how it goes with the new one in next week