I would like to share a mistake I made during my K75T restoration so that someone else might not repeat it 
When I do bike restorations, I usually run a tap saturated with WD-40 through all the threads of just about everything I disassemble. Then I clean the threads out with brake cleaner and compressed air. This is to get the rust and debris out so I can get a clean torque as well as ensure everything comes apart cleanly if/when I need to service the component again in the future.
While replacing my exhaust manifold studs, I ran the tap into the threads in the cylinder head. I didn't realize until it was too late that these holes were machined with tapered threads to hold the studs! I noticed filings coming out with my tap when I extracted it. So afterward, I realized the studs screwed into the cylinder head very cleanly and bottomed out in the hole, making the studs too short to get the entire copper nut on fully to hold the exhaust flange. This prevented the locking part of the nut to engage enough threads to offer any resistance. So I had to put the nuts on the studs first, then screw the nut and stud in together like a bolt.
I was thinking of other creative ways to solve this problem, but this seemed to be the most straight forward. Here are some options I considered:
1) I tried using some thin jam nuts to lock the studs against the cylinder head, but I couldn't find ones that were thin enough to not cause an exhaust leak. The flange always made contact with the jam nuts.
2) I decided any kind of lock-tite would be a waste of time, so I didn't try any chemical bonding agents
3) I thought about installing longer studs, but had a fear that I didn't want the studs to bottom out in the holes. I'm not exactly sure why I feel this way, but it just seems wrong.
4) I thought about putting a ball bearing inside each of the holes to offer a little more length on the stock studs, since they'd bottom out on the ball bearing, but for the same fear I had in #3, I decided I didn't want these studs bottoming out.
5) I thought about using some vice grips to lightly mangle the middle threads of the studs so they'd offer resistance at that point when screwing them into the head, but then I thought that would be a mistake in the long term because of potential damage it could cause to the threads in the cylinder head. It probably would have worked, but isn't a clean fix.
Can you guys think of any other ideas to handle this problem? To thread the nuts onto the studs, I locked 2 steel nuts together on one end of the stud, then holding it with a wrench, I threaded the copper nut onto the other end of the stud until about 3 or 4 mm of stud was showing through the locking part of the nut. Then, I just threaded them in like bolts a little bit at a time in a criss-cross pattern. Everything torqued up fine and there were no leaks, even after 350 miles.
Thanks,
Ty
). I was replacing all exhaust studs last year. The job was bolt off, bolt in kind. I have used so called locking screws. That means no head, only thread, but with hex port on one end. This way there was no additional nuts required for bolting new studs. Instead of OEM copper nuts, I have used self locking one time crush nuts (the one slightly oval when bought new). 