1992 XT600 E

Work done:

- Bored cylinder 1mm over and am using a 96mm wiseco piston.
- Shop that did the work supposedly followed wiseco's instructions
- Replaced oil pump with new one (3aj)

Problem:

The bike runs but is dumping a steady stream of oil out of the oil tank vent hose when the oil tank fill cap is installed. Without the cap, the bike runs perfectly. Not one drop comes out of the vent hose without the cap.

I have good oil flow. At first, I thought I had overfilled the engine with oil. So I dumped it and refilled according to the instructions I found in the few threads that I found on this subject. I am sure that it is now filled to the correct level. I checked it after riding it around a few miles with the oil tank fill cap off.

The only thing I can think is the cankcase vents somehow became blocked or are not going where they are supposed to. There's two vents, right? Both have a hose but the other end is not plugged in anywhere, should one be going to the air box? Would this make the difference?

Other possible issue that came to mind was that the shop did not follow wiseco's instructions for boring the cylinder and somehow this is creating pressure back up the oil system?

I am at a loss here.

Any help is appreciated. Thanks.

Ok....

By looking at this diagram I can see that the oil tank vent hose (#6) heads down towards the area where the cankcase has a vent. I'm assuming it should plug in there? If this is correct, then the other breather (right underneath the starter motor) is the one that connects into the airbox. Correct? When I got this bike, this was all a mess and i've been trying to put the pieces of the puzzle back together myself. Any help will be greatly appreciated. If anyone could take a picture or two for me of the hoses, where they plug in and how they are routed I will buy you a , or two or 6 next time you're in Colorado .

Thanks!

Just answered my own questions:

#1 is the oil tank breather hose and #2 is the crankcase breather that I assume goes to the airbox...



I will report back when this is done.

I know one of the hoses is connected NOWHERE...it just sticks out to the floor so the engine gets rid of the excess oil (when it heats it expands)... which one is it....uhmmm I don't remember...My XT600E is in the garage waiting for me to go back home to Azores this Easter and Summer :P

Ciao!

Vando