First off there is a major probem on the Super Tigers that no one has mentioned. The carb barrel has a rough finish that will grab and lock the throttle in one position.
Didn't mention it 'cause I've never experienced it or heard of others having problems with the barrel. Maybe because I drip Dextron III ATF in as after-run oil it stays slick?
I did have a throttle arm pull off a lightly used Kangke SK-50. Most other problems have been "self inflicted" from dirt naps and such.