troy1

I just rebuilt the top end in my 91 exciter 2 with a 570 liquid and it is bored out .020 over. There was no noticeble piston slap when we installed the cyliders onto the pistons. I am still geting a bit of a tap/knocking noise from the front/bottom end of the crank case near the starter. My friend said his brother has the same machine and it sounds exactly the same. Is this a normal noise for the yamaha 570? If not how much bigger of a job is it to replace the crankshaft bearings than what i already did with the top end rebuild? I assume its pretty much what i already went through with the top end but just involves popping the crankcase apart and having bearings and seals pressed onto the crank at a machine shop. We did take a look at the connecting rod bearings while we were there and did not notice any play in those.

troy1

It also seems to be worse when first started, and hardly noticable when revved up a bit if that makes a difference.

troy1

well i got some replies to my question from another thread and finally got around to checking the clutch and everyone was right. on the out side of the clutch are some roller bushings and i think this is going to be my culprit. two of the three have no play but on the third one if i squeeze the two sides of the clutch together i get a little bit of movement. the shop i talk to said its only a half hour job to replace this and it should take care of the issue. the sled is running mint. its hard to start on really cold days though, the choke cable is freezing up. but once its warm it runs like a top. i did manage to break the weld on the handle bars last weekend. that was a fun ride back using a pair of vise grips. i also managed to crash into a gaurd rail at the end of the ride after we rigged the handle bars directly to the clamp to finish the day. steel grate bridges and sleds don't like eachother much. the sled was going straight then wham, it just kinda jumped to the side and smashed my ski up. the guy watching from his truck was rolling in the cab. can't say i blame him, i was laughing a bit to. any ways thanks for all the help folks, i'm sure i will have plenty more questions in the future. i think i have found my drug of choice for the winter months, snowmobiling. it's fun, exciting, and you get to get out and meet some really cool people.

kccats

Wow you really sumed it up there! Welcome to the snow show!