I noticed on my DS that it NEVER smoked at all ever!. I could sit in neutral and hold it to the rev limiter and ABSOLUTLY NO blue smoke would EVER come out, which made me feel good because I knew my motor is like new... Well you all know that I bent my valves and had to pull my head off to have a buddy install and re grind the valve seat and so on. Ever since I got my DS put back together I noticed that if I rev my quad up in neutral that it puffs a tiny bit of blue smoke when the motor deaccelarates back to idle. Now it didn't bother me at all, but I got thinking that IT NEVER smoked even a tiny bit before. So I never did ask my buddy, but the first thing that came to my mind is possibly the valve seals wern't replaced when he installed the valves?? Worn valve seal would cause that right? If it were the rings it would smoke all the time when I rev it up, so I know it can't be that. I been keeping an eye on this to make sure it isn't getting worse or anything and it's not getting any worse at all. Just when I rev it up, when it comes back to idle it'll puff a tad of blue smoke. You can barly notice it unless you're really paying attention. So this isn't gonna hurt anything or decrease performance or anything like that will it? Do you think it would be slightly worn valve seals that's causing this? Do I have anything to worry about here?

Thanks.

 

Bought a chevy truck, new in 87, and it had the small block. Well every one knows they blow the blues at startup, even when it was new, and ya, it 's the valve guides. Anyway, its got 250,000 miles now, still puffs blue on startup, and I've never had the engine open, everything is still stock inside.
point is...dont sweat the small stuff, oil is cheap.

 

well.... It don't use ANY oil. (don't smoke enough to burn a noticable amount) And it don't smoke at all on start up.... ONLY when I crack the throttle when it idles down. It's not bothering me at all but I been keeping an eye on it in case it gets worse. I don't think it would be my valve guides, but the valve guide seals???

 

I have had my ksf 250 mojave built like a grandnational and it never smokes until I had the head flowed and ported it did smoke when I rev'ed it up and it decreased in rpm I used to complain about it but they said it was normal when I had the new valves in it that the specs are so close when they are built from the factory that it is almost impossable for it to be spec'd out perfectly I don't think you have anything to worry about I really never used oil for I changed it every 6 hours of running the bike.

 

LOL, sounds like me too. For one the smoke is barley noticeable so it don't even burn enough to consume oil, and I change oil often.

 

You're in nuetral and pinning it to the rev limiter?!![img]i/expressions/face-icon-small-shocked.gif[/img] Well golly, I would have never thought to try that!

 

When you let off the throttle after revving it there is a lot of vacuum in the cylinder because the butterfly in the carb is closed. Its sucking oil past the valve seals. Its a shame he didn't put new ones in, they're less than $4.00 each. Now you'll have to buy another $50 head gasket unless someone does it without pulling the head. Unless the smoke doesn't bother you.

 

With the rev limiter set only to 7700RPM on the stock CDI I could hold the dam thing to the limiter in neutral all day and it wouldn't hurt anything......

 

Well the smoke NOW don't bother me at all, but I'm just worried about it getting worse. It hasn't been getting worse but if it happens to I guess I'll pull the head off again........[img]i/expressions/face-icon-small-frown.gif[/img]

 

TTT.