This 1991-92 model is equipped with a blade brake clutch. When the blade slows down this means the belt is slipping. This slipping can be caused from a few different things.
1 --A loose cable.
Try adjusting the blade cable on the upper handle. this unit has an adjustable section. make sure the cable is not so tight that you snap it.
2 --A sticky pivot point under the belt cover
The belt cover in the back builds up with dirt and debris. Make sude it is clean under the cover and all of the pivots move freely. ( do this with the engine off)
3 --A sticky belt tensioner under the deck cover
The underside of this machine has a metal cover to protect the belts. Remove it and check that the blade belt idler arm is not frozen in place. this will cause the belt not to enguage all the way.
4 --A worn belt or belt pulley
The large flywheel and pulley can wear. Check this if the belt looks good.
This is all there is to the machine BBC system.
I hope this helps.

Get parts and more diagrams at a Master Toro Dealer like www.arcolawn.com
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