Re: Now I own *two* DAX GT50r motors........
Yes, Head bolts on these engines are the weak link.
Mine got loose after my 1st ride & good thing I thought to check them out.
The way I did it was to remove one, use Red Loctite on the threads, then tighten it back up nice & snug before removing the next one for the same treatment & so on.
I also was getting loosening of the spark plug. I removed it, checked the gap, & used Blue Loctite on just the threads closest to the spark plug gasket...All have remained tight since.
Another buddy of mine just blew his Stage 3 engine on the 2nd day of ownership due to loosening head bolts....This seems to be the achilles heel of these pocketbike engines...