Wr426 oil loss through crankcase breather hose

My '02 Wr426 is blowing a significant amount of oil out of the crank case breather hose. After maybe a 50 mintue ride (45mph roads) i've lost about 1/3 of the oil on the dipstick measurement, and the skid plate is pretty well oiled with a few drops accumulating.

 

Definately not being caused by too much oil added.

 

I suspect worn rings? However bike still has great compression, always starts with one or two kicks no matter the situtation and has original power. Bike does have a significant amount of miles/hours on it, and is mostly street ridden.

 

Valve seat/seal issue is suspect #2 but definitely leaning more towards rings.

 

Any opinions/prior experience?

Thanks

 

I'm going to go with new rings.

Are you talking about the breather that runs just under the ignition cover on the left side frame rail?  I would think a ring would be suspect if I was to guess.

 

While it's not loosing nearly as much as yours is mine does accumulate more oil in that area than my brothers from what we've noticed.  Not sure why.   

 

Keep us posted on what you find out  :ride:

Edited by Rot Box

It sounds like one of the other breathers are pinched or clogged.

Rings would not do that and still run.

You should do a leak-down test anyway on a motor that old....

im having the same problem but how can rings cause oil to reach breathers ?

the compression that is supposed to stay on top of the piston leaks by  the rings and pressurizes the crank case  all that pressure tries to go out through the breather and it caries oil vapor/droplets with it on the way out

Edited by Zimman

It sounds like one of the other breathers are pinched or clogged.

Rings would not do that and still run.

You should do a leak-down test anyway on a motor that old....

A leak down would be a good idea.

 

I believe all the other breathers are just off the carb, and maybe ones a coolant over-boil/flow. So I don't think they have an impact here; could be wrong though. 

I'm going to replace the piston, rings, and obviously gaskets in the near future here, I'll report back on the outcome.

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