cleaning crank area

[Still biking]

Is there any way of flushing the crank area out when you are replacing a cylinder and piston other than removing engine and splitting open? 

[Barrie]

What do you think is down there ? Gasket material, the odd circlip, use compressed air line.

[Dvsrd]

Or use a clean cotton rag, and use the crank to pull it around. Just make sure you can pull it back out the same way it went in, if it gets stuck.

[quocle603]

Or use a clean cotton rag, and use the crank to pull it around. Just make sure you can pull it back out the same way it went in, if it gets stuck.

[Striker1423]

You could flush the bottom end out with gasoline followed by premix to re-oil the bearings. Compressed air works too. But, if its really got chunks of stuff flying around, you would be better served splitting the cases and cleaning things out properly.

[Djg8493]

You could flush the bottom end out with gasoline followed by premix to re-oil the bearings. Compressed air works too. But, if its really got chunks of stuff flying around, you would be better served splitting the cases and cleaning things out properly.

Agree, diesel works good as well

[Still biking]

What do you think is down there ? Gasket material, the odd circlip, use compressed air line.

aluminum dust from piston failure

[m in sc]

id split cases.

[27 Cycles]

Yup, I just went through this...  I tried to clean it out for hours..  finally split the cases, it would have been bad news if I didn't.  Better safe than sorry.

[pdxjim]

What do you think is down there ? Gasket material, the odd circlip, use compressed air line.

aluminum dust from piston failure

I spoke with RB about this a few years (a decade at least) ago after ventilating a piston on my TDR.



To paraphrase:  "Sure, we used to do it all the time.  If time is of the essence, like between races or at the height of the riding season, then flushing with diesel or kerosene is acceptable.  Pull the engine out of the frame, and fill the case with solvent.  Spin the crank until it spins freely with no sticky spots.  Dump out the solvent, and repeat until you run out of clean solvent.  Then cross your fingers and run it.  Chances are, if the bearings were good before, you'll be fine."

Otherwise, split the cases and do it right.