mystery oil in 75 cb crankcase

[were trees]

iput a quart of mystery oil in my crankcase.
then i read in the clymer not to put additives in there.
to wash it with kerosene"the crancase"
its says its bad for the clutch is this true?

[niterider]

I think that mystery oil is a lot like automatic trans oil. I think you will be okay just drain the oil and refill the crank case with fresh oil. Don't add stuff like stp treatments, they are very slippery and make the clucth slip.

[TechTMW]

Mystery oil is a decent crancase additive as it coats the metal parts and protects them from acids and whatnot. It also is smaller than dirt on a mollecular level so it cleans out dirty stuff fairly well. It's also good to add a spoonful to your gas tank every now and then to prevent rust.

That being said, all you should need is a tablespoon in the crankcase for these benefits, any more could hurt the clutch.

Do as suggested, drain the MM out VERY THOROUGHLY and throw some regular oil in there, hopefully should be fine.

[Skier]

I've run Marvel Mystery Oil (MMO) in my bike's oil a few times. Not in that large of quantities, though.

I think you'll be just fine if you put a little bit in the crankcase, run it for a hundred or so miles, then change the oil. The MMO will clean out a lot of gunk and buildup in the motor, so don't be surprised if the oil comes out looking really dark.