I own a Yard Machine from MTD... 15 HORSE POWER, 42 inches... yardmachine
Model No. 13A6672G129... and my constant problem iw with belts.

1. what would be the correct/appropriatge belt for this particular model?

2. whenever I changed belt (PURCHASED FROM HOME DEPOT)... claimed to be the appropriate belt... the belt did not last long... it would work for about 3-4 hours and break loose.
a. the belt gets longer (lengthened) and got out of the pulley... thereby refusing
To cut.
Or
b. the belt might be used (eaten/gets thinner) on one side more than the other side..
And eventually will disengage complete from the pulley... I checked the alignment
Of the pulley and they appear to be in line (in the neutral position... blades do not
Engage

c. at the back of the belt (at its widest point).. opposite to the inner potion of thebelt into the pulley.. there are traces that appeqar that the belt is hitting (friction) at some point and I was not able to locate where.
d. I am using about three belts per month.

Appreciate anysuggestion to the above problems''
Thanks

Chris

What the deck uses to keep the belt from popping off is belt keepers... and could be overlapping one...
Also check to see if ALL the pulleys move freely... should keep spinning for a second or two after you fling them around.