Here goes......I have a 1992 Yamaha Exciter 570 II LE that suddenly started bogging horribly. The carbs were cleaned an re-jetted for a Bender single pipe that was put on. The sled ran great for a couple weeks. I was out riding the snowmobile last week, slowed to cross a road, gave then sled some gas and BOG....the snowmobile started bogging. Tried a new belt and plugs, still bogged. I got the sled home, checked the compression and I had 120+/120+ in the two cyliders. Good compression. I found a seized carrier idler wheel on the suspension that was worn down into the aluminum of the wheel. I changed the wheel and put new bearings on both wheels on either side. The sled still bogged. Upon further inspection, I noticed the secondary clutch had a ton of play in it. I inspected further and found that the jackshaft bearing had gone out, beyond seizing to nothing left and the jackshaft bearing housing was cracked and ruined. The jackshaft bearing housing and bearing were replaced. The jackshaft was still in good shape so just the bearing and housing were replaced. The sled STILL bogs! The sled starts great, idles perfect and revs up awesome -> with belt off it revs up awesome. The primary clutch seems to operate great, compressing and decompressing with the rpms of the motor. I can get on the sled and drive to like 10-15 MPH starting out with no problems but as soon as I get on the throttle a bit, she bogs down and if I crack the throttle open, the sled really slows down and barely moves. As soon as I let up the throttle, right back to perfect idle and a slow cruise. TORS system is disconnected and hooked into itself just like everyone does it. I think it is a secondary clutch issue. The spring is fine, but is it possible that when the jackshaft bearing went out and seized for a bit, the spring slipped out of one of the holes into a different one or into one of the 3 different settings in the secondary? Which setting is the average normal setting on the inside of the secondary, A....B....or C??? The belt also seems to sit like 1/8 inch into the sheaves on the secondary now, is that too far in when just sitting still? This problem is really frustrating and Winter is disappearing quickly, does anyone have ANY ideas??? Thank you very much for any help!!
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