Purchased a old kart that had seen better days put new harbor freight motor on it and ordered a torque converter unit from eBay both driver driven and belt. It’s a 20 series setup with a symmetrical belt and the driven is mounted on the onboard side of the jack shaft. Now this started out pretty good for my daughter she’s 13 well her older sister wanted to ride as well. Done goof for a bit but now the driver opens up so much the belt drops down to the rivits and locks up sometime you can just push it back always and it will walk out but most of the time it’s a prying event. The belt is not to tight and at idle it slips fine. Any clues that I can look at thanks