I noticed that my '99 Sportsman 500 (Fuji motor) has a faint trail of blue smoke behind it from time to time. I can't tell yet if it is smoking during throttle on (rings?) or throttle off situations (valve guides?). Periodic oil checks show that if it is burning oil it's not using much yet. I keep the oiling system in good shape using Polaris 0W40 and new filter at each change.

Can I just hone the cylinder and re-ring it or is money better spent going with the re-bore / new piston & rings route? What is different / better about the Wiseco setup over stock Polaris pistons. Is the Wiseco lighter? If so, what does that mean in application? Faster revs? What have you experienced?

 

To do only a ring job, your cylinder wear must be minimal. You will have to measure in several places to be sure that the cylinder wear is uniform and has not worn more in one area than another. If the wear is out of spec, you will have to bore out the cylinder and replace the piston with a larger one. Wiseco is the way to go, lighter and more durable. As far as where the oil is coming from (valve guides or rings), go to the "Tech Connection" of atvconnection.com and read post #402. It explains how to do a compression test that will distinguish between ring wear and valve guide wear.

In my opinion, you will have more longevity from a top end rebuild if you rebore it. Use a reputable shop that does motorcycles, snowmobiles, outboard marine engines, etc. It should cost you about 50 dollars to have the cylinder bored if you bring it to them. Bring them the new piston so they bore the cylinder to match it.

Farmer123 has an excellent post on this forum telling you how to tear down your top end. Good Luck.