i went to check the air filter on my kodiak today and noticed oil all over the airbox (mostly underneath) and all behind the oil filter. The oil filter seems tight, has no leaks around the o-ring i can see, and has only a small spot of oil on it. other than that, i have never wrecked or rolled my kodiak, and except for some hard-pounding at the ATV rallies, the bike has seen a decent life (i ride it very hard, but never put it away wet). In fact, upon closer thought, the only wreck i've had on the bike was a nose-stander i did last summer after jumping a make-shift dirtpile launch (a good 8- 10 feet is possible) and nothing was broken after that (i checked her over good).

Any ideas?

 

You're all good. If your Kodiak is anything like the newer ones, it's your rear diff vent tube. It runs from the diff to right on top of the airbox. If there's a lot of spilled fluid, check your rear diff fluid level and make sure it wasn't overfilled. I don't know what Yamaha was thinking when they put the vent tube on top of the airbox, but they know more than I do... Some people have rerouted theirs.

 

I too have that problem and it was leaking over onto the exhaust and onto the top of the belt housing. I first thought this was the crank case vent and was a thinking I had put to much oil in after the oil change. I spoke to the dealer and they said it was do to water in the diff housing and they said I must of been going thru realy deep water. I explained to them I had 50 miles on it and very little water crossings and nothing over a foot in depth. The next thing they said was condesation from sitting in the shop heating up and cooling. Anybody heard of this? I know it is getting rerouted to another place. I do not like the smell of burning oil in the motor, Napalm yes, oil no. AlaskaBoy.