Rear disc brake dragging thus causing the brake cylinder to heat up and I have to release the bleeder valve a bit then tighten back to loosen up the brake so the tires will spin. Also the chain comes quite frequently. Any solutions to these problems will be helpful. 110 cc

 

replace the caliper. as for the chain, verify it's lined up and straight. then check the chain tensioners and make sure they're not broken or fouled up somehow. if they don't have lock washers on them, they should. heck, the tensioners may have springs on them. are they ok and intact? good luck.

 

ok so the chain tensioners also act as alignment for the rear axle. Well the tacks that hold the tensioner have broke causing alignment issues. Also it looks like that they welded the rear crooked from the factory.