Check the spark plug to see if it shows signs of burning oil or running rich (Fuel) Sounds like you are burning oil. Keep an eye on how much you are using. the problem could be rings, it could also be valve stem seals or valve guides which might be easier to fix. It should be possible to change the valve stem seals with out disassembly of the engine. on the off chance it may be a fuel problem check the choke adjustment, and float level. Running with the choke partially on would make it smoke also. (Fuel ecomony would be down) I get 20 or 21 MPG in 2wd, and about 17mpg in 4wd on my 450 foreman es. With out seeing the bike it is hard to tell why it is smoking. The spark plug may give some insight as to the problem if you know how to "read" it. Also any unusual engine noises could give a clue. I am relativly new to ATV's. I started out working on small engines and old motorcycles back in the late 60's and was a professional auto mechanic (and some gas powered equipment like stump grinders and the like) for about 25 years. My experience with ATV's in not extensive, but basic mechanics is all the same. I hope this helps you some. Keep us posted.

 

Well I finally got some time to work on the thing. First I warmed the engine and took the air filter off, well that didn't help. So I cleaned the plug, major carbon build up, again no help. But I did notice that it's not smoking while rev'd-up, it only smokes when you let off the throttle and the revs are comming down, (not sure if that's important).

Anyway, next I drained the oil and here's the dead give away, gas in the oil. The oil was really runny and probably had more gas in it than the gas tank did. The oil filter look like crap. So I replace the filter put oil back in it. Warmed it up and of course it still smokes. So I am going to call the dealer back tell him the situation and probably I will take it in.

I only hope they can honor the warranty. A friend of mine said he had a 450 Foreman start smoking after about 3 months. Eventually it smoked continually, he took it the same dealer which I had bought mine and they told him that it was not covered under the warranty. He did not want to pay for the repairss he sold it. Not sure if he was really hard on the machine or what, It may have been a completely different situation.

Thanks for all the input, I'll keep you posted on what happens.

Later,
Mark

 

sounds like you have a stuck float, or needle and seat, and while it sits, it fills up the motor with gas. It comes in from the top, and washes the oil from the cylinder and rings. Then when you start it up, the rings run dry for awhile. Not sounding good.

 

I have put about 15 - 20 miles on it since it started smoking. Hoping that I have not done any major damage to it.

 

I called the dealer back to tell him what I had found. He said to turn the gas valve off open the drain on the carb let the float settle then open the tank valve and let if flush through the carb. Close the drain and keep the tank valve closed until you start it again.

Close that tank valve every time you stop for more than a few minutes. He said this was a very common problem and if I keep the gas turned off that I should not have any problems from it. Oh well that's probably a good habbit to get into anyway.

 

After flushing the carb. I have let it sit for a few days with the gas turn off. I started it and ran it for a while this weekend. It ran great adn had no smoke. I hope this takes care of the problem. Just gotta remember to keep that gas turned off. Thanks for all the input. Gotta love these forums.