I have been having a few problems with my '91. I have a rough idle, no power (as in torque). This afternoon I was going over a few things trying to figure out what the problem might be(was thinking in the ball park of rings and pistons before I started) I had the tank off and removed the top of the airbix and air filter; there was oil laying in the bottom of the air box. Not sure how it got there thought maybe the oil breather that comes up in the right side of the box. I started the bike and let it idle, no oil came up but a thick cloud of white smoke started pouring out of the oil breather hole, not a small amount but a lot. The smoke wasn't tinted blue and didnt smell like burning oil but actual exhaust fumes. Any clues?? and when I gave it a little gas(up to about 2500-3000 rpms) a little bit of oil sprayed out of the breather hole.

I drained the oil and only had the recomended 3.4qts so it wasnt like there was too much and it was using the airbox as a run off.

any help would be great.

Anyway to tell if the rings are bad without a compression test?

 

this sounds like a problem i am dealing with too.

 

It's normal to get a little oil in the bottom of the airbox. It comes up through a breather hose. But you shouldn't have puddles of oil or anything like that.

Not sure about the smoke. I don't spend a lot of time running my bike with the airbox open.

How about running some real diagnostics. Do a compression or leakdown test. That will tell you if you've got a ring or piston problem. If that's fine, then make sure all your hoses are routed to the right places.

 

Thanks for the help first off.

I figured it was normal to get a little oil in the air box but I had a lot and that in turn was the reason I ran the bike with the airbox open to see where the oil was coming from. which in turn I saw the smoke.

I don't know anyone who has a compression tester and going to the shop for that would be a bit pricey I imagine. One of my friends said about a leak down test too. Do you happen to know how long it should roughly take?

 

Something that I have done in a pinch as a pro mechanic is to disable the ignition system and crank it over. Listen to the cadance or rythym of the engine while cranking, it should be nice and even. If you have a hole with very low compression the starter motor won't be under as much load when on compression on that hole. The starter motor along with the engine will speed up for that cyl, and it will upset that nice even rythym. It will only tell you if you have a catostrophic failure which unfortunatly it seems to me you may very well have. It may not be something for the layman and it does not replace real data from real tests but in a few seconds it can give me a clue into whats going on, whether a bike is worth buying or in your case whether it's something that's going to need more attention.

Good luck and remember working on the damn things is supposed to be part of the fun too!