If you're blowing white smoke when the engine is warm I have to agree with the others who say it could be coolant leaking into the cyclinder. I believe you can check this by putting a compression gauge on the cylinder (screws into the spark plug oil) and see how long it takes it leak down. Maybe someone can advise us both on how long it should hold pressure. A leaking head gasket will reduce this time significantly.

I guess another option would be to do the same with the coolant system. It should keep an almost constant pressure without a leak somewhere in the system.

I don't see any connection between the color of the smoke and the tranmission. However, the Rubicon does make use a unique design where I believe engine oil is used to operate a hydraulic pump which in turn controls the transmission.

Check all the easy things that have been mentioned here first like the oil levels and colors of the spark plug and oil. Thinking of that, might your friend have gotten water in the oil during the recent outing?

If I had to guess, I would say it was simply running rich before (black smoke) and that he later got water in the oil (white smoke). The increased throttle is enough to lessen the effect of water in the oil (white smoke at idle) and the rich condition is made worse (black smoke) when the throttle is opened up.

 

Right after you leave water or if it dies in the water, your exhaust will be white. This is from the packing getting wet. It will continue to do this until it dries out. If you were in over your muffler, did you have anything snorkeled? If not, you have other problems. If you were not snorkeled there is water in your: coolant overflow, front diff, rear final gear, front brakes, rear brake, carb bowl, etc.

 

The snorkel under his seat never went under. And it was smoking b4 we went through the water. And his front brake doesnt work, but the rear one a little bit.

 

I have had my rubicon over its seat in water crossing a river almost daily for a long time now. I have never had water in any of the components listed above. As long as you have the throttle open and the quad fairly level there's no problem.

 

I assure you, you will have problems eventually. The coolant overflow is the lowest snorkel on the quad. Other than that, the others are vented into the frame about 6 inches under the pod. They are by no means waterproof.

 

Thanx for all the help I have tried everything, takin to the shop probally.