briggs ohv single 331777

[backhoelover]

unit keeps shearing flywheel key. everything is grease free. i also lapped the flywheel and shaft together. have also tried steel key lol busted the other flywheel that was on the motor. threaded hole on shaft where flywheel bolt goes is clean. any other idea. thinking im going to have to remove sump and take a look.

 

[Stump Shot]

The taper is not holding. Check for any minor disruption in the flywheel and the crankshaft. The key is only there for alignment and should only shear if something stops the motor dead from WOT, like hitting a stump with a lawnmower for example. Once assembled take the nut off and give a moderate/mild rap with a brass hammer to the crankshaft with pressure on the flywheel if it comes right off, it's not holding good. Should take a fairly hard/sharp rap with a brass hammer to remove.

 

[AVB]

Reference Briggs ASPI #89. Engine prior to date code 120630xxxxxxx had a bad crankshaft design and was prone to shearing the keys. Basically for prior 120630 you use a steel key, add a washer under the flywheel bolt, and increase torque to 110 ft-lbs.

 

[backhoelover]

pulled it up on my briggs power portal it doesnt give a part number for the new key

 

[backhoelover]

the motor has newer shaft and the flywheel on it is the newer style. guess i need the new key dont know how that will help but i will try it