Exhaust studs

[750SuperSport]

The 1980 super sport I just purchased has zero rust anywhere on it except for the exhaust studs... and they’re really rusty and stuck in the heads. I tried the double nut trick with heat to back them off and lost that battle. What’s my next step. Drill them out?

 

[amc49]

Good luck with that, it generally leads to scrapped heads. That year was the small 6 mm. ones and they broke left and right, the next year Honda changed to 8 mm. and even those will break but not as common.

Drilling by hand commonly makes the drill bit hunt for the softer aluminum around the steel stud to drift at the drilling to go way off and then the hole is scrap. You have a compound angle on those holes.

The long exposure to water and heat lets them corrode inside the holes to weld them in place essentially. If I ever take them out I antiseize them going back in but the thing is to leave them in place.

 

[750SuperSport]

Yikes. That’s a kick in the nads. I guess I’ll weld a nut on and see if the heat from welding is enough for it to break free. If that doesn’t work maybe I’ll take the heads into work and machine the studs out.

 

[750SuperSport]

On second thought.. would it most likely behoove me to knock the exterior rust off and keep them in? I guess I don’t really need to remove them. I was just being OCD about making sure I’ve addressed every nut, bolt, and stud.

 

[dirtdigger]

If they are not broke might consider just leaving them in. If you must take them out or if you broke one off, first try welding a nut on like you said, it is my preferred way of doing it. Turn the heat up high so you really get some heat in it and good penetration, mig welder really is the best for doing this. Let it cool couple of minutes hit it with some good knockerloose, wd etc. I also tap on stud with hammer and start working it with a wrench. Youll either start to make it move or you'll break the nut off. Sometimes have to weld another nut or two on it but I almost always get them out. Last resort is file the stud flat, get a good sharp center punch and make sure you get it centered. Then drill and try easy out. If hole gets damaged you still have some options, could drill and tap to larger size stud or use heli coil inserts. Kind of up to you if not broke you may just want to run them.

 

[amc49]

Skills figure in there bigtime. I personally do not say how to much as every one I approach in a somewhat different fashion and the technique changes by the minute. I do know I don't double nut much on the 6 mm. ones as it loads the stud at the threaded portion, I instead go inboard on the stud to be working with the unthreaded shank as it is stronger being the stress riser threads are not there. I too am anal about getting them out but really not needed unless one is porting the head and why I would be removing them. Other than that and say a machinist saying he wants them out to do some certain machine operation there is no need to remove them in and of themselves.

 

[Chris in Dorset England]

leave them alone, at least you know they won't fall out