250crf tranny and egine oil issues

[dmdee99]

I have a 2004 crf250 and when I went to change the tranny and engine oil it seems that I have more engine oil than tranny fluid than what I started with.

I do not see any leaks from the cases and the bike runs fairly strong. My buddy said that I may have a bad crank seal. Is this correct?

If this is correct how hard is it to change it? Do I have to split the cases? :whoa:

I was going to change the top end because I am getting oil out of the breather hole thinking that the rings are bad but I still have good compression. Could this be why the oil is coming out of the hole or is that just another problem that I have to fix. :|

Any help would be appreciated.

Thank

 

[Matt90GT]

This is called oil migration in the bike.

I have experience from my 450. Here is what you will need:

right side crank seal
right side cover gasket and any water pump o rings there for the dowls
both bearings for the counterbalancer and the seal for the counter balancer
left side cover gasket


you will need to move both left and right side case covers. Remove counterbalancer nut, and the shaft. remove the seal and drive out both bearings. replace. Then pull the crank gear (after removing the clutch basket) and replace that seal. Be sure to polish the counterbalancer shaft before reinstalling.

 

[dmdee99]

Thanks

I will go and order the parts. Do you think this is also causing the oil out of the breather hole? Or is it just worn rings?

 

[mideastrider]

Matt is correct, however the LH balancer bearing on the 250 maybe more difficult to change than the 450. But for sure change the Rh bearing. Take note of the timing marks on the balancer shaft to the crank shaft. Yes the excessive oil that is entering the engine from the tranny will cause oil out the breather tube.

 

[dmdee99]

Thanks