Arthur wrote on 07/06/09 at 14:17:13:ralfyguy wrote on 07/06/09 at 14:09:53:On some applications on the bike, you shouldn't use stainless steel bolts, as there is a certain bolt strength required. You shouldn't replace bolts with for example 10.8 or worse 12.9 rating, as SS bolts don't even get close to that. Stainless steel is a somewhat tough but not hard material, and is not suitable for cylinder heads and such. I have worked with this stuff for years. You tighten one down and it seems to stretch like rubber. Therefore use it only where strength is secondary. I have lots of SS bolts on my bike, but nowhere safety related.
Absolutely right! Do not use stainless for head bolts for anything requiring heavy torque. They break easily. I always use grade 8 for any serious applications.
Okay, so I shouldn't use SS on the main head bolts. Seems like the head cover/cam assembly should be okay, though, right? What about the clutch cover and generator cover? Anybody had any experience with those, and what are your opinions?
As a side note, the one bolt I thought had broken when attaching the head cover/cam assembly to the head, I found out when I extracted it again it wasn't broken at all. Upon closer examination, I saw that it had a heli-coil on it, so the internal threads must have been stripped. Evidently the heli-coil is not longer effective, so I have to redo it. Never used heli-coil before. Does anyone have any advice on how to use it?