Craftsman drive wheels won't stop

[Jbgibbs]

I have Craftsman 917.388740 self-propelled mower that has lasted more than 20 years with no repairs other than 1 carburetor replacememt, a few blades & oil. It has cast iron cylinder & I don't want to replace it til engine dies. My problem: Original drive belt stretched & no longer had enough tension even with adjustment to move wheels. Sears online & phone parts, as will as other online parts stores, no longer show drive mechanism on their parts diagrams or list a belt. So don't know what size belt to get. Took old belt to shop & they sold me new belt a little shorter (for $20!) which I installed & used adjusting knob on drive lever. Now it takes off at high speed with lever in off position. Removed corrosion & polished inner surface of drive pulley. Took lever mechanism apart to make sure cable travels full amount & lubricated cable which slides easily. Reassembled & problem persist. Does anybody know correct belt size for this model or have other recommendations?

 

[mechanic mark]

Craftsman 917388740 gas walk-behind mower parts | Sears PartsDirect

Craftsman 917388740 gas walk-behind mower parts - manufacturer-approved parts for a proper fit every time! We also have installation guides, diagrams and manuals to help you along the way!

www.searspartsdirect.com

Are you sure you have the correct model number because this is a walk behind mower?

 

[Jbgibbs]

Why won't it post my pics? I'm using jpg files from my phone camera that I shrank down to around 50KB.

 

[Jbgibbs]

To answer your question, yes, unless a mechanic switched the sticker. I'm trying to post pic of model number sticker.

 

[Jbgibbs]

Problem resolved. It seems the problem was not a worn belt. In the process of trying different sized belts, i lubricated the tensioner cable and cleaned the cobwebs and dust that collected in the tension control mechanism. After several belts were either too short or too long, I reinstalled the old cable and it now works. Lesson learned: If after some years the belt no longer tightens enough, don't jump to the conclusion that there's a problem with the belt. Someone else said, belts don't usually stretch after initial break in. This seems logical. Unless these belt is seriously worn, the problem is more likely in the cable and tensioner mechanism. Thank you for following and contributing.