I have a B&S 5.6 Intec. The friction plate is slipping and smokes after about a minute of riding (it is on a go-cart). Any troubleshooting ideas?

Friction plate??

Are you talking about the centrifugal clutch??

That is definitely what I am talking about, got any ideas?

Possible brake dragging.

Throttle limit may be set to low, not allowing sufficient RPM's for complete clutch engagement.

Excess wear on clutch shoes.

Oil, or grease from clutch bushing or bearing has leaked into clutch drum.

Just a few ideas off the top of my head.

I cannot look at it tonight, too dark, but the throttle is set as low as it will go to keep my kids from rolling over on their heads.
Will check throttle in the morning, thanks a lot.