Where's the smoke coming from?
 

I have a 2003 arctic cat 250 2x4. Has been rode pretty hard and is smoking now. I checked the compression and its between 150 and 155 psi. With that kind of compression the rings should still be good right? And if that is the case is the oil coming from the valves and if so does anyone know what it takes to fix them.

Thanks

Where's the smoke coming from?
 

When does it smoke?
Cold, hot, all the time, idle, hard throttle?
What color is the smoke?
Are you having to add oil, how much, how often?
What weight and kind of oil are you using?
Check the plug, is there alot of carbon buildup on it?
Is your airfilter clean?

Where's the smoke coming from?
 

OH....and welcome to the forum! [img]i/expressions/face-icon-small-happy.gif[/img]

Where's the smoke coming from?
 

The service manual says that compression should be 157.5 - 192.5 on a warm engine with the throttle held wide open. So I would say you do have a problem. Try pouring 1 oz of oil down the cylinder and re-check. If it has got higher then your rings are bad, if not then it is your valves. Also, it might not hurt to check and make sure your valves are within the correct range, they could have came loose.

Where's the smoke coming from?
 

Thanks for the welcome! It starts fine and I think runs pretty good for a 250. Just recently acquired it to hunt with and not as strong as my 335 Polaris but that is expected. Not quite sure of the history but I haven't really rode it that much. I put synthetic 5w30w oil in it and a new plug and cleaned the air filter. I think it needs some adjusting on the idle speed as it seems to low. It does seem to smoke all the time and seems like more the harder you get on the throttle. Its a blue color smoke. Haven't rode it enuff to know if I need to add oil. Would the choke position have anything to do with it? I wouldn't think so. I have never had to work on atvs but it would seem to me that oil has to be getting into the cylinder to smoke. But that is why I am on here. And fyi, it smoked when I got it and it is smoking the same after everything I did to it to "tune it up". Thanks again for the help.

Where's the smoke coming from?
 

And one more thing. DOes anybody know who makes this motor? I have heard Suzuki, Kawasaki and Kymco. Can't find anything on the engine. 2003 arctic cat 250 2x4. Even called arctic cat and they were no help.

Thanks

Where's the smoke coming from?
 

Suzuki makes it

Where's the smoke coming from?
 

Suzuki makes the motor on that 2003 model.

From what you have said 3 things come to mind for it to be smoking.
1) Valve stems are worn. Which as long as its not burning too much oil and fouling the plug. I do not see any harm in continuing to ride it.

2) Overfilled with oil. Could be sucking excess oil back through the crankcase vent. I think you should notice this on the air filter though.

3) Partial blow-by around the rings. As was already mentioned this can be checked by removing the spark plug and squirting some oil into the cylinder. then recheck compression.

Hope this ehlps
SJ