I have an 03 700 that has 110 hrs on it and recently it has started smoking when I am in the upper rpms, dont notice it so much at low rpm. Starts and runs fine until it gets warmed up pretty good then it starts to cut out and you have to stay on the throttle or it will die. Checked the oil and it was almost a qt low after about 1 hr engine run time. Filled it back up and ran it a little more and used more oil. Took it to Polaris dealer and he replaced a bunch of carb parts, air filter etc. and said "it runs like a charm but still smokes, could just be in the muffler". since getting it back I have only put about .3 hrs on it and it still smokes badly, I have not got it to full operating temp to see if it cuts out but it looks as if it is still using oil. I would appreciate any suggestions on what to look for next.

 

Check the rings. Oil may be blowing by. Check the coolant and pray the oil isn't in there.

 

I have checked the coolant and it is fine. Is it a big deal to check the rings on a 4-stroke, have not worked to much with them. I have done many top ends on Honda and KTM 2 strokes but not 4 strokes.

 

Check in the airbox where the PCV goes into it. See if there is any oil in the airbox that may be getting sucked into the motor through there. If so then you have a lot of blow-by which means the compression rings are gone. If not then most likely the oil rings are gone. I think either way you will have to change the rings. It's not a hard job. It's a pushrod motor just like the honda so you won't have to mess with the timing to do the job.

 

As it heats up probably loosing compression along with oil ring blowby, advise to teardown, check for partial piston seizure,plus check ring end gap and piston to cyl clearance. If past .003 worn!

 

thanks for your replies.

 

if its not your rings I have seen a couple of these with cylinder wall plating peel off of the casting, just another thing to look at while you have it apart.