(click here)

Mr. Know It All



By Rondo Talbot

Please be gentle.  I have a 71 400 Maico Square Barrel.  Overall the bike has been pretty reliable.  My main problem that keeps recurring is the cylinder studs keep coming loose.  As you know the cylinder studs run from the  cases through to the head.  The studs seem to be coming loose from the cases first.  I would like to know the proper torque specs for the studs and the proper technique to tighten every thing down, such as lock tight or not.  Are they loosening because of repeated heating, cooling cycles?  Do I just live with a torque wrench from now on?  Your shared wisdom would be appreciated and acted upon.                             
Loose Nuts 
Mr. Loose Nuts,
I'm trying hard not to paraphrase Black Flag in this answer, so please excuse me...
Your studs are loosening because the studs are shot. When studs get old, the threads tend to stretch out, and no amout of torquing will alleviate the stud from loosening up. A 400 square barrel had 13mm studs, almost 1/2 an inch, so they are pretty stout, and go into the cases a long way.
Get some new studs, and put a drop of oil on the end that goes into the case, double-up the head bolts so they lock, and torque the stud down to 30 ft. lbs. Get some new head bolts too, and you won't have any more issues like the one you just described. Don't use locktite, it is not necessary with a stud of that size.
Now if your nuts are loose, might I suggest some lind of support, like a jock strap or tighty-whities? I'm a boxer man myself, and allow my nuts to float freely as nature intended. I've found that if my nuts are too tight, I can't think straight, and my mind's a mess...
Oh yes, and you really should have known.
(with apologies to Henry Rollins)