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fritz73

Dripping oil from hose

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I have an '01 WR426. Just had the motor rebuild over the summer. Why do I have oil dripping out of the large breather hose that comes out of the valve cover? This hose is about 1/2 inch in diameter comes from the valve cover and loops its way under the motor. Any help would be great.

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I have an '01 WR426. Just had the motor rebuild over the summer. Why do I have oil dripping out of the large breather hose that comes out of the valve cover? This hose is about 1/2 inch in diameter comes from the valve cover and loops its way under the motor. Any help would be great.

Some is normal, excess means pressure is leaking past the rings and filling the crankcase with some extra pressure (blowby gasses), if it was just rebuilt, it will take a little while for the rings to seat.

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Thanks for your explaination MDT Tech. I understand better. But how long does it take for the rings to seat? I probably have a couple hundred miles on the bike since the rebuild.

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Too much oil can also be the problem - have you checked your oil level the CORRECT way? Here's the procedure for my 2000 wr400:

1. start and idle bike for 2 minutes

2. Shut off, let sit for 30 seconds

3. hold bike level, take out dip stick, wipe, insert but don't screw in pull out and check level mark.

Any other way will give you a false reading according to Yamaha.

Lots of people reroute this breather into the airbox to avoid staining the concrete in their garage, also, the factory location can casue you to suck in water if you ever stall it while the hose end is submerged. A simple T in the line up high can avoid the sucking up of water.

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I am probably putting 5 oz of oil back into the bike each time I ride. There is a small puddle under the bike when I park it for the night which leads me to believe there is a continuous leak when riding. The dip stick is always bone dry when I check it before I go and I do Matt4x4's method to check.

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It's one of three things...

1. Too much oil

2. Rings are still seating

3. Rebuild has gone wrong

If you've put any kind of mileage on the rebuild, then I would probably go with number 3 unfortunately. If you paid to have it rebuilt, take it back...SC

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ASK specificlly for a Cylinder leakage test and that you want to see the written results of the test. You also would like to know if there is significant leakage where is the leak presenting itself. (i.e. exhaust pipe, air box, engine breather hose)

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Thanks Cannon. That is a great idea. I'll let you know what happens. As a side note...the bike is hard to start as well.

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