Crankshaft Nut at Varator comes loose every 1200 m

[chihuahuas]

139qmb 39mm bore
Stock setup max speed 32 mph
Crankshaft nut comes loose every 1200 miles. Like clock work.
Crankshaft replaced at 12000 miles. New crank does same thing.
Have used glue/locktight still same results.
Anybody else seen this.

[nulldevice]

If it is the flywheel nut I would inspect the taper to make sure both pieces have the same taper, the keyway and key match and are in good shape, use a new nut and if it has one a new washer, and put the flywheel on DRY, no lube on the taper, threads, or nut. You might need a new flywheel.

I have had variators fall off, but it was my fault every time. Here the errors I have found -- the hard way.
Are you sure it is torqued properly?
Is the washer, if used, between the nut and variator in place?
Are you using the correct type nut -- my scooters use flange nuts, no washers.
The nut may be countersunk, make sure it is facing the right direction.
Have you replaced the nut as well?
The blue medium strength locktight didn't hold?
Did you use the correct surface cleaner correctly
Did you wait 20-30 minutes before starting the motor?
Are you sure you aren't pinching the belt as you tighten the nut? That would make you think you are tightening the variator but you aren't.

More details may produce more ideas.

[rae4180]

Ya make sure the belt is lose and out of the way when you tighten it down. locktight should work. if not get some white teflon tape.