Installing new exhaust header bolts...

[SD_Dave]

I've removed the old rusty exhaust header bolts from a 1980SG engine. I used BP Blaster and two nuts jammed together to wrench 'em out. The tapped holes look ok to me.

Question: Should I use Locktite on the new bolts? Any words of wisdom pertaining to installing the new bolts?

BTW, this is my first post on XS650.com. I am doing a complete tear-down/clean-up/re-build of a 1980 650SG. I am soooooo glad this website is here! There is so much knowledge and information available here. Even though I put over 50K miles on a brand new '78 650 that I owned (and loved) for many years, I am just now learning the innards of the 650 bike.

 

[b1broc]

no loctite buddy! not there anyways

 

[jd750ace]

To protect them from siezing, coat them with milk of magnesia before installation. Same thing when putting the acorn nuts on. Keeps moisture out of the area between the aluminum and the steel, so it does not corrode and sieze.

 

[Purplezinger]

Coat the threads with Never-Seez. This is an anti-seize compound that will handle the high temps associated with exhaust. Use NO Locktight in this area. Wire brush the threads first (if you are reusing the old studs).

 

[jd750ace]

M.O.M. is cheaper than never seez!

 

[SD_Dave]

Thanks all...
Also, I searched but couldn't find a torque spec for the bolts...is there one? And what about torque on the exhaust cap nuts?

 

[FrkyMnky]

It would be worthwhile to clean up the threads in the head and clean off the stud with a brush. Loctite is useless there simply b/c of the heat unless you get the special high heat stuff. Be sure to use a high temp anti-seize that is designed for different metals otherwise you will have one causing the other to corrode.

 

[SD_Dave]

Torque specs anyone? Thanks!

 

[SD_Dave]

Bump...on torque specs...Ok, maybe just snug the bolts tight...sound about right?

 

[ReycleBill]

I always just snug mine. Just make sure your copper ring is in good shape and there's not an old ring stuck inside.

 

[SD_Dave]

Errr...copper ring? What copper ring is that...?

 

[5twins]

The seal ring that the head pipe seals against.

 

[jd750ace]

There are copper crush seals between the head pipe and the cylinder to cushion and seal the joint. This is a reason to be correct in the torque of the studs. I'll find something useful for ya later.

 

[SD_Dave]

Oh, THAT copper ring. Right...

 

[jchrisk1]

Copper rings??? Am I missing something? Mine only has those coiled paper gaskets. Are you talking about the ring that slides over the pipe and goes up against the collar?

 

[ReycleBill]

There are supposed to be copper rings (crush seals) that go inside the head between the pipe and the head. They often get destroyed and stuck inside the head. Other times they fall out unseen when the pipe is pulled from the head.

 

[SD_Dave]

Final bump on the torque specs for the header bolts...anyone?

 

[jd750ace]

Here's some good stuff for ya.

http://thexscafedotcom.wordpress.com/2011/01/18/xs650-torque-settings/

When you install them, torque them to spec, run the motor enough to get to full operating temp, something like a 10-15 mile run.
After it cools all the way down, torque them again. Repeat until the nuts do not turn at the prescribed torque, indicating they are stable. Usually takes 2-3 cycles for everything to fully seat in and torque to stabilize.

 

[SD_Dave]

OK, so if the 8mm exhaust nut is spec'd to 9.5 ftlbs, then I guess the bolts s/b somewhat tighter, at say, 11 ftlbs.

Great stuff, jd750ace...thanks much!

 

[jd750ace]

Look on down the page and check the standard torque values. 11 Ft. Lb is standard for 8MM threads.

You got it!