Exhaust Studs

SteelyCR

SteelyCR

PR Member
I've been riding the struggle bus with my 97 CR125 top end rebuild, but my latest obstacle is the exhaust studs.

To make a long story short, I just wanted to see if anyone had any expertise on installing new exhaust studs. On the studs, there's a long side and there's a shorter side of threads. The longer side is supposed to go in the cylinder if I'm correct.

I'm using two nuts tightened together on the stud in order to tighten down the studs. The threads are so short that you can't even get two small nuts completely on the threads. It seems as if the threads on the studs are getting messed up from using this method, because afterwards a good nut will not smoothly thread on to the stud.

I got brand new studs and nuts, but it appears that the threads on at least 2 of the studs are now messed up.

Has anyone run into this issue?
 
That's what I do, really never had an issue. Maybe try just one nut tightened down to the bottom of the threads and spin it in that way.
 
The bike manuals show using that technique but I have always been concerned with distorting the threads, or worse yet, snapping the stud below the nuts.

I have a small 4" or 5" pipe wrench, fits in palm of hand. I use it on the unthreaded area of the stud. The only downfall is it sometimes leaves bite marks on the stud that need smoothed with a file. Works great. I just removed head studs on a cylinder I recently sent out for service couple weeks ago.
 
I cut the width down on two nuts on a lathe. If you don't have access to a lathe, you could even grind them down holding them with vice grips. There is also a tool for installing / removing studs that won't hurt the threads.
 
Thanks for the tips guys. The Honda service manual doesn't indicate a torque value for these studs. How tight should they be? These are 6mm studs. The head studs are 8mm, and it says 9 ft/lbs for those.

Also, I don't think there is a torque value for the nuts either, how tight should those be?

Lastly, does anyone put threadlocker on exhaust studs? I figured it would probably get too hot for that anyways. Plus, the one hole goes into the area where the powervalve rod is (which has lube on it).

Thank you!
 
I've never put lock tight on an exhaust stud. The last ones I did, I put never seize on them and ran them in with the 2 nuts. If there's no room for both nuts how about a cap nut.
 
Why not run a tap in the hole and screw them in with your fingers? If you have already goofed up the threads beyond your liking, run a chase die on it. That should clean them up just fine.
 
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