Snowmobile Racing

Im thinking of putting new rings on my 98 Doo 700 tripple.

It has over 5000 miles, but they dont look to bad, no siezes or anything like that.

Are aftermarket SPI any good ? I always thought OEM was the way to go but they are 4 times as much money. Or would I be better off keeping the originals in there.

thanks, crs

Racing or trail? Good oil keeps the rings free in the grooves.Whats the compression? Check piston to cly clearance.Check for cracked skirts.I like Wiseco.Does anyone use SPI in Drag Racing?I know the Factory Polaris SnoX TEAM uses SPI.

Trail with some play racing.

Good compression, skirts are fine wasent going to do the pistons, just new rings on the old pistons.

The old rings are free and good in the groves, the top ring has a little discoloration in the top portion of the ring sidewall.

Compressions good-run it!

Even though the ring feels good in the groove,  mic it or check with a feeler gauge,  what appears to be .002" could be .005".  Also check the ring end gap with the ring in the cylinder at its location with the piston in the cyl.   Also mic the piston skirt where the cam is (usually 1/2" from the bottom of the skirt) to the cyl bore.

Attention to detail is important.

if you want to know the true condition of a cylinder then i suggest a leak down test,anything 5% or less is good 5 to 10% is usable anything over 10% and i would recomend correcting the problem

Thanks for the replys fellas.

I think its OK, I have it appart fixing a oring groove blow out so figured might as well replace the rings but looks like that are still good.