1981 SS440 Clutch help

[bandersonh]

Here's my question, I have restored an 81 SS440. When I got it the belt was so tight that the only way to start it was to have the track off the ground.
I researched everywhere I could find to make sure I knew what belt it should have and ordered one, that didn't help. I then figured I'd loosen engine mount bolts and make sure engine was back all they way to decrease the CTC distance. That didn't help either. Now I can only guess that my secondary is not the correct part and slightly bigger than what is supposed to be there???? Any thoughts?

I currently open the secondary by hand and then start it and get it to drive away. I tops out at about 6500 rpm's as far as I can tell. Once you slow down it will drag again and die.

Thanks,

Brian

 

[Throttle Junkie35]

I bet some time in your sled's life some one removed a shim from the secondary to compensate for a worn belt. There should be two shims between the sheaves. To make sure the secondary is the correct one, the part number on it should be 8K4. it may have been swapped to an 8OL part number, but it will not make a difference.

 

[bandersonh]

I bet some time in your sled's life some one removed a shim from the secondary to compensate for a worn belt. There should be two shims between the sheaves. To make sure the secondary is the correct one, the part number on it should be 8K4. it may have been swapped to an 8OL part number, but it will not make a difference.

Thanks for the response. It does say 8k4 on it so I guess that's correct. I don't understand how shims or lack of could increase the CTC to make a belt too tight... i guess unless it simply keeps the sheaves further apart to let the belt sit down lower???

 

[Throttle Junkie35]

Yep. You add or remove shims to correct the belt deflection. The belt should be flush, or close to flush with the top of the secondary sheaves. BTW, C2C should be about 10-9/16"

 

[bandersonh]

Yep. You add or remove shims to correct the belt deflection. The belt should be flush, or close to flush with the top of the secondary sheaves. BTW, C2C should be about 10-9/16"

Belt is basically flush, when I manually open the secondary so it will start easily and not pull I have the belt down in secondary almost an inch. I have not measured CTC yet so will do that.

Thanks for the help.

 

[Throttle Junkie35]

Sounds like the wrong belt. I STRONGLY recommend an OEM yamaha belt part number 89X-17641-01-00. Should be about $40 from your local dealer. Fitment problems do arise quite often with aftermarket belts.