Originally Posted by FMB42
I installed a set of upgraded cylinder/head studs and nuts on my 66cc. Cleaned the threads on the studs, nuts, and engine cases followed by torquing the studs to the cases @ 9 ft-lbs. Man, what a diff these studs are over the bent and soft factory studs. The increased basic and/or "over-all" major diameter of the threads on these upgraded studs does a much better job of indexing both cylinder and head during installation (the threads on both the upgraded and the factory studs are rolled btw).
Most, if not all, of the other cheap factory fasteners will get the same treatment...i.e. tossed into the garbage.
That's why sick bike parts has the sets already bagged. Stud set for the head and a set for the rest of the bolts. I don't know what the Chinee make the bolts from but Grade 0 is being generous. I had all kinds of problems with the stock motor mount bolts. Replaced them with Grade 5 bolts from ACE. No more problems.