No, it should not spin the motor when off.  I had the same issue when I first moved to a KT100 and clutch.  If there is a a spacer, you may need to sand it down a bit – at least that is what was wrong in my case.  If the starter nut is coming off, check the bearing in the 3rd mount.  If it is not spinning freely then it can cause the starter nut to back out.  This ruined my race weekend a couple months back.

Good luck!

Are you talking the engine or the clutch spin when you turn over the rear wheel? The clutch drum should spin with the chain/wheel, but the engine crank should stay in the same position if not running. If you spin the rear wheel, and you feel the force of the piston going up and down, then you have installed the clutch wrong and it is in direct drive.

Robert,
If the piston is traveling up and down when you turn the rear wheels, you do have some sort of clutch failure or the clutch is out of adjustment. Before you do anything, do you have the L&T tools to remove and service the clutch? The starting point with clutch slip should be around 6k and adjust towards a higher engagement RPM. Never start at 11K and turn to work your way downwards. All you’ll have that way is smoke. You should end up between 7.2 and 8.5k.
For the clutch not turning freely, if this is a new clutch, there is the possibility that the adjustment screws are way off. If not a new clutch, disassemble the clutch and carefully measure everything as specified in the manual. Have found that the dog bones do wear and break. If you have a kart shop in your area, ask if they would help.
As for the starter nut, check how far in the clutch goes on the crank shaft with and without the key in the shaft. Your key could be too large and not allowing the clutch to fit tightly on the shaft.
Also, L&T has a phone and fax numbers plus email. I’d give them a call.
Good Luck

Installing the clutch and installing the seat, the 2 biggest pains in karting.

Gif

Robert,

Any update?