I bought I bought an engine kit a while back and finally got around to installing it. I bought it off the Wish app so I really don't know what manufacturer or model ionly that it's 80cc. I used a kit from bikeberry for the motor mounts and it had thick rubber bushings and long studs. I had to use that because the motor would not fit in my frame otherwise. Then the chain was rubbing the frame, so I use the tensioner sort of as a guide and turned it inward slightly just enough that the chain actually had clearance. I took the bike out and it was a lot of fun I don't think it did more than about 15 miles an hour. 2 things I noticed is it was very rattly and at full speed the motor would actually wag left and right just a little bit is that normal? Also when I had it at Full Throttle the bike would alternate running smooth and bogging down. After riding for a little while I went to go pull out of a side street and the motor spun around shearing off both bolts in the front of the motor. I've seen posts about cutting a groove in the bolts but they an 1/16 to an 1/8th in the bolt hole, I'm afraid to weeken the block or have a cracked start because of it. So I'm going to take it to the machine shop to get them removed. Is it worth trying to tap bigger bolts in there?