I bought my son a new 300ex 2 days ago.I noticed riding behind him on my recon that when he was shifting that a puff of white smoke would come out.Not a lot but noticable.Now today while riding it still does it but not as bad as the first day.also it has a very raspy idel not the smooth sound that my recon has.also the engin gets really hot when i went to check the oil i could hardly hold the dipstick becuse it was so hot.does this sound normal for this machine.Thanks............................

 

did u buy the quad new or used, if used maybe the top end needs rebiult but i wouldnt think that should happen on a 4 stroke unless that happens when it is still getting broke in then maybe its natural im not sure about this one though

 

kkkiller300ex's new 300ex smokes like a 2 stroke and his doesn't have a nice idle either. I'm not sure why but I think it may be the rings. I dont see how it could be the rings gone bad allready seeing as it's a fourstroke and it's a 2001. He is going to get it checked out sometime , ask him about it.

Does your sons 300ex only puff out white smoke ? Kkkiller's 300ex smokes blue. Also try changing the oil that may be it. If there is any water in the oil that will cause white smoke. Good luck , Zeebo

 

Well if your sons qaud is new and still geting broken in then i think its natural to smoke mine did and KKKILLER250x is wrong about it idling bad it idles fine it does have a little blue smoke coming out the pipe but not like a two stroke it only does this when it really hot???

 

Dude,yours idles yes, I never said it didn't idle , but it doesnt idle smooth its rough and yours smokes like crazy it smokes everytime we ride so your motor must have an over heating problem too.


Also jockgordo yes the dipstick should be too hot to hold thats normal . But it's not "natural" for the motor to be smoking like that. You should call up your dealer and ask him if he knows what it mat be. Good luck , Zeebo

 

im taking off the top end and seeing if their is a problem in their and if not ill check out the entire motor?

 

The smoking problem would only be coming from the top end. The crank would have nothing to do with it. Mine smokes up on start up but after its warmed up its ok. Its because a worn valve guide or its been rebulit and has a Wiseco piston.

 

I took the 300 to the shop today.all is well i was told that the smoke is just from the rings have not seated yet.they are chrome so they are very hard.also the raspy idle is ok .my other son bought a raptor while we were waiting on the 300,what a monster,now i have my choice of atv's to ride.
thanks...................

 

The 99 300EX that I had before my Raptor purchase didn't have the smoke when it was new. I did change my oil and install a new filter after the first full day of riding just to get all small metal particles out. If you change your filter look between the pleats or folds of the filter. Also clean the pan spotless that you are going to dump the old oil in and you will be able to see if there is any metal if you hold it up to a light. I know son is going to treally like his Raptor. 31 hrs on mine and just had valves adjusted. There will be more hours added today though after I post this I'am getting our KDX and Raptor out of the garage. Chet