Snowmobile Forum banner

21 - 33 of 33 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #21
Ok I may have found the problem, while i was starting to check the rings I noticed a gouge in one of the cylinders, cant believe i didn't see it before. Im going to assume that this gouge totals that cylinder.
 

Attachments

·
Registered
Joined
·
1,032 Posts
That was caused by a piston ring. And no it doesn't total the cylinder. You can bore it out, you send it to a shop to bore it out and have them match up a set of pistons and rings so they fit perfectly. I've seen cuts worse then that and they've done a bore job on the cylinder. Or what you could do is have the shop yank that cylinder sleeve out and put a new one in with stock specs but that is usually much more costly.
 

·
Super Moderator
Joined
·
1,857 Posts
Dont sleeve it just have it replated.
I have sent US Chrome jugs with pieces missing and they welded and repaired and plated and come back better than new!
I would send Both jugs along with 2 pistons!
 

·
Registered
Joined
·
1,032 Posts
Forgot about the replated you can do on those. Best to do it that way and have the said pistons matched up as I said in above post. And yep best to do both now while it is apart so they are a matched set.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #25
Is only 250 for a new cylinder that might be cheaper. I live in ohio so there exactly isnt any shops around me. So if anyone has some good suggestions for shipping Id like to get an estimate and see if its just cheaper for a whole new cylinder. Also I still want to check the compression rings where would i find information on tolerances for them?
 

·
Registered
Joined
·
11 Posts
Discussion Starter #27
I want to make sure the rings are within limits and are okay. Since that could also be a likely problem for low compression's besides the gash.
 

·
Registered
Joined
·
1,032 Posts
Hence why you replace them. Finding the specs on those is going to be hard almost no one has them. Even when I worked at a dealership we never re-used rings or checked them we just tossed them and replaced them. That is what everyone does. You are the first person I've met in 41 years of snowmobiling that has ever asked for ring specs on a sled. Not like this is a race car engine where you can get that stuff easily.
 

·
Registered
Joined
·
3,587 Posts
I replace them, but I do check the new ones for specs as well. It has never happened to me, but a friend got rings with a piston kit that were the wrong size. His were suppose to be for a 78 mm piston and the ones he got were for a 77mm They still went on, and it wasn't obvious they were wrong.
 

·
Registered
Joined
·
1,032 Posts
Checking for that to see if the size is the correct ones for the pistons you are using in a new build yeah most definitely. But checking for the original specs meaning the tolerances are still within use nope never seen that before. Most likely that gash was done by a ring. When I was drag racing at Chicagoland I and many others would re-use rings on our car engines but those tolerance specs were easy to get within 5 minutes. Usually when we were rebuilding it wasn't a ring issue it was a bearing issue or a cam issue from all the abuse we put them through in such a short distance.
 

·
Registered
Joined
·
3,587 Posts
Wish I was closer, I'd take it off your hands.
 
21 - 33 of 33 Posts
Top