If it ever strips out again Drill, Heli Coil it to 1/4-20 as mentioed above, use red locktite on the Heli coil and get you some 1/4-20 Grade 8 allen head bolts and you are done with that issue for ever and ever....! Just (DO NOT) PUT THE RED LOCKTITE ON THE GRADE 8 BOLTS USE BLUE ON THEM....!
I've thought about going ahead and doing this to my intake and exhaust and motor mount threads on my extra engine so that when I get ready to set it up these things will be resolved from having issue from the Git Go.
Good luck with the hair pin though, hope it gets you there and back a 1000 times over..!
Happy MAPBIKING.... (Motor-Assisted-Pedal-Bike)