Deck Belt Comes Off Craftsman Rider

[R4665]

Craftsman DYT4000 917.275684

Purchased used Craftsman Riding Mower that Is in great condition. Runs great. Put on new belt a five months ago when I purchased it.
- Periodically the deck belt comes off the pulley attached to the electronic clutch on the crankshaft when I shut off the clutch. When the belt comes off, the belt is "twisted". The back of the belt is on the crankshaft. I have to twist the belt so the "V" will fit into the pulley.
- The five month old belt is frayed on the bottom of the belt.
- There is no belt keeper on the deck pulley on the crankshaft or the parts diagram which I find odd. There is a belt keeper on the drive pulley. All the belt keepers on deck appear good.
- The belt seems tight after I put it back on.

First mower I've owned with electronic clutch, so not sure how to troubleshoot.

Ideas? Suggestions?

Thanks

[RoyM]

An idler may be mis aligned or badly worn.

[KE4AVB]

Yes this don't a belt retainer at the PTO clutch due the constant tension on the belt. Just seen my first one of this design about a month ago here.

Curious. What size belt did you install? Sounds the belt may be over heating especially since it is likely a poly belt. I showing it is a 5/8 x 97.5-97.625. I see several places are pushing the 97" belt. Also make sure you have the idler return spring in place along with the drive spring on the moveable idler arm.

And Roy said check the bearings on the deck; both the spindles and idlers.

[R4665]

What size belt did you install?

This was a MaxPower Belt 336317. Belt size is 21/32-inch x 97.4-inch
Replacement for OEM 174883.

check the bearings on the deck; both the spindles and idlers.

make sure you have the idler return spring in place along with the drive spring on the moveable idler arm.

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Will do.