Mower destroyed new belt

[Deadwake]

Hi,
Have a question about my craftsman lt1000. I have been trying to get my mower going again for a while now and today was supposed to be the day I mowed for the first time since I had to put a new engine in it. Instead it burned out the new belt. The model of my tractor is 917271842. The engine I put in is 12.5hp model # 286707. The belt I put on was an equivalent to p/n# 532144959. The belt seemed a little tight but there was some slack. It smoked a lot and burned through minutes after engaging the blades. Could it be because of the engine swap and I need a bigger belt or did I get a bad belt? Please help.

 

[ILENGINE]

Most likely cause is you missed a belt guide around one of the idler pulleys, or didn't get the belt installed around the spindle pulleys correctly. Some have brake arms on the spindle pulleys that also act as belt guides when the deck is shut off. if you didn't get the belt between the pulley and the brake arm it can also cause the same issue.

 

[Deadwake]

Went and rechecked how I ran the belt and didn't seem like I missed anything. Pulling the remains of the belt everything spins like it should. But talking to my father he reminded me that the belt should have had a descent amount of slack which it didn't, it only had a little play. The belt I bought was 95"x1/2". Could it have been a wrong size belt? I don't think I need a bigger belt because when I swapped the engine the original drive belt fit. Should I try a longer belt or am I still missing something on the cutting deck?

 

[bertsmobile1]

The actual belt length is 95.375" A section ( 1/2") Wrapped kevlar belt.
a difference of 3/8" will really not make much in the way of difference and usually not cause the belt to burn & break.
Did this happen while you were mowing or while you were driving ?
I have found that on some mowers with manual PTOs if the blade brakes are not working properly the slack in the belt does not end up at the engine pulley so the engine pulley burns the belt.
Once a belt is burned, that burn spot will just get worse and slip on every pulley till the bent snaps.

Having said all of the above, the replay from Illengine hit the nail on the head.
It is very easy to miss a belt keeper and have the belt running on it and not the pulley
What we need is to se the belt.
The damage to the belt will tell you why the belt broke.
Almost every mower shop has a belt damage chart hanging up somewhere and Husqvarna has a really good one ( full coiour ) on line.
All of the belt companies also have a damage chart on their web sites bit most are black & white which makes it harder to see the characteristics of the different types of damage.

 

[Deadwake]

Thank you guys for trying to help me. I think I had figured it out but the belt is now the least of my worries. I was going to post pics but just a little while ago the engine died. It appears the Piston arm broke and the Piston head is seized in the cylinder.