Well here I am another JRSC belt victim. I was wondering if the crank pulley could be adjusted to align my pulley situation better. It seems if the crank pulley was more closer to the block like about one rib of the belt then it would stop coming off. It always comes off one rib towards the block when reved to the max, then gets shredded from dragging on the timing cover.

Any place make custom pulleys in California? I would like to get pulleys with side walls to keep it in track no matter how hard I drive. I wish I could wind up my motor like before man it really sucks holding back. I need help!!!

 

i think your problem may be with the bracket not your crank pulley somethings not allighned anymore if its off one rib.

 

Yeah I thought that and it only comes off when I beat on it. So maybe its flexing at high rpms only. Boy it's gonna be a bitch trying to get that broken bolt out.

 

I am having the same problem as you but mine is jumping 1 rib the other direction on the shock tower only when i beat on it will it come off. really starting to **** me off been trying to figure this out for a month now.

 

I had an issue the other day myself it was my own fault though I replaced the upper tensioner pulley and the belt was riding the edge of it . The blower belt seems to ride on one side of the top tensioner anyway . I actually had to remove the upper tensioner pulley and the cone shaped spacer behind it and file down the spacer so the belt would not ride the edge of the pulley filing down the spacer moved the tensioner in like I needed . If a machine shop had been open that day I would have went to them to have it done it took me a while to file the spacer down but it worked like a charm .I would not play with the crank pulley. I would look into the pulley alignment of the jrsc pullies . The crank is not something I personally would put any type of spacer on or even fool with I would be looking elsewhere for the issue causing belt failures. I boost the **** out of mine and beat it like a red headed step child my belts do have somewhat of a short life span but thats just the nature of the jrsc especially at 13 lbs LOL