How big of a difference is there between Dennis Kirk pistons and Wisco? It seems crazy to spend the extra money on this "piston eater". Also, what jets should be used for normal trail riding in minnesota? I know they are finnicky.
"Dennis Kirk has high-quality, OEM-type piston assemblies to fit most popular snowmobiles. These pistons more closely match the original equipment in ring design, construction and weight than our other aftermarket pistons."
I dont think Dennis Kirk sells their own brand of pistons - those piston that you see, are aftermarket brand. It just happens that Dennis Kirk sells them. Aftermarket brand pistons are a little different than OEM brand, cheaper but not a better quality. What do you mean by, "piston eaters"?? Are you referring that your sled keeps blowing up? If thats the case, before you buy anything, find out why it keeps eating up pistons. Check out this site and maybe you can find out what your problem is. Read it carefully, especially down at the bottom. http://eric-gorr.com/twostktech/pistondiaguide_2t.html
Hopefully you'd find the real problem. Anyone? WL.
Thank You all!!
The web link was some good info white lightning...The center cyl. had a broken skirt, which tells me this motor was at one time honed past std. cyl dia. This is my first time into this motor. (it's my uncle's) I'll have all cylinders checked and oversize if needed. I haven't split the case yet, but what are the chances of crank damage with all those big chunks of skirt flying around in there?
My suggestion to my uncle is.....put in a new domestic twin...anyone know if this is an easy transplant?
Ok so if that is the case, see if the cylinder can be bored out and put in an oversized piston. Before to put the motor back together - split the case open and check and see how the crank is. If the crank is ok, be sure you wash it out really good. Before installing the crank back in, be sure you add fresh new seals on both ends (PTO side and the mag. side) As you put everything back in, do it slowly and do it right. If the crank is bad - you have an options of getting it rebuild, find another used crank elsewhere, or find another 650 motor. I would avoid putting in USA twin, being you would have to get a change everything, meaning more work than you have to. Im not saying it cant be done - are you willing to take up some challenges? Personally, I would try to fix the motor or find another 650 - it would be easier to put it back together. Anyone? WL.
Oh I forgot to mention, I know people are going to voice their opinions regarding on oversize pistons, if you have to bore out .010 in the middle cylinder - you would be safe to run it that way while the other two cylinders are in std. size. If one needs to be bore out .020 over, then you'll have to do the same on all cylinders. If you dont, it can create an unbalance spin in the motor and it can cause alot of damages inside. Personally, I'd rather play it safe and have it all cylinders bored out .020 if I cant get away with .010 on one cylinder. WL.
Hey Monkey L.A. Sleve out of California makes OEM style pistons for that motor. They make them up to .060 over if I remember right at a pretty reasonable cost. If you want I can get the number for you. Riley
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