Exhaust Headers

[Middy2000]

Got an advisory for an exhaust leak and it's on the webbed section of the headers where they meet.  Was going to explore option of welding it as I'm aware of the nightmares people have with the studs.

Decided to have a tentative fiddle and to my amazement (relief) all 8 nuts turn. The ones I can see it's definitely nut and not stud that's turning.

So....should i replace the nuts only or when I fit new headers should I remove the studs and replace too?

[fazersharp]

I wouldn't push your luck, I don't know anyone who has tried to remove the studs, likely they have "welded" themselves due to that different metal thingy.
Welding might make it worse unless you are good at very thin welding.
I have small holes also in the collector area and have filled with JB Weld high heat putty and so far has lasted 2 years - other stuff I have tried has fallen out after about 500 miles.   

[Middy2000]

I've used JB Weld to good effect before so might be an option but given that nuts are moving I'm confident i can get the headers of.  It was just a case of whether I tried the studs too.

[fazersharp]

As no one has chipped in I will say again if the studs look good then leave them well be as they are made out of cheese like a lot of the parts on our bike.How do you propose to get them off - with the two nut locknut method if so then consider that is how people end up snapping the studs because the nut is rusted on.

[agricola]

Leave the studs alone, count your blessings, and buy a lottery ticket

[Middy2000]

Message received loud and clear. The studs can stay put.  Don't fix what's not broken.

So any recommendations for replacement headers? Black widow been mentioned.
Also replacement bolts? People mention dome headed ones. Any links?

[robbo]

When I needed to replace my header nuts I went for stainless, but also bought domed headed ones in stainless as well, also known as acorn nuts. The idea being that once the studs have been copper slipped and the bolts tightened, the exposed thread is covered by the domed nuts purely to protect the exposed area. Once in a while you could slacken off the domed nuts, reapply some copper slip and retighten.

[agricola]

if you go for dome nuts, make sure that the thread on the stud does not contact with the dome inside when torqued up, easy to get this wrong as the gaskets will compress when the nuts are tihjtened and lead to the stud tightening against the dome inner, givine the feeling that its fitted correctly when it isnt. A simpler option is to use connector nuts so its not a problem how much thread is exposed https://www.screwfix.com/p/easyfix-a2-stainless-steel-threaded-rod-connecting-nuts-m6-10-pack/4720g


[Edited to fix the broken link: GrahamM - Moderator]

[fazersharp]

if you go for dome nuts, make sure that the thread on the stud does not contact with the dome inside when torqued up, easy to get this wrong as the gaskets will compress when the nuts are tihjtened and lead to the stud tightening against the dome inner, givine the feeling that its fitted correctly when it isnt. A simpler option is to use connector nuts so its not a problem how much thread is exposed https://www.screwfix.com/p/easyfix-a2-stainless-steel-threaded-rod-connecting-nuts-m6-10-pack/4720g


[Edited to fix the broken link: GrahamM - Moderator]

Good tip with the connector nuts. The acorn nuts can be had with elongated heads but you still might have the problem of bottoming out. As the OEM nut has a flange has anyone also added a washer.

[b1k3rdude]

The phrase Sharp was possibly looking for is 'galvanic corrosion' where you have 2 dissimilar metals (Aluminium alloy of the cylinder head and the mild steels of the studs.

If the studs arent badly corroded, and the outer threads are serviceable, then as has been suggested leave them be. If however they are a rusty mess, take it to a professional for them to remove, do not try it yourself and if you can remove the engine as it makes access for that person a lot easier.

[fazersharp]

The phrase Sharp was possibly looking for is 'galvanic corrosion' where you have 2 dissimilar metals (Aluminium alloy of the cylinder head and the mild steels of the studs.

That's the monkey 

[robbo]

if you go for dome nuts, make sure that the thread on the stud does not contact with the dome inside when torqued up, easy to get this wrong as the gaskets will compress when the nuts are tihjtened and lead to the stud tightening against the dome inner, givine the feeling that its fitted correctly when it isnt. A simpler option is to use connector nuts so its not a problem how much thread is exposed https://www.screwfix.com/p/easyfix-a2-stainless-steel-threaded-rod-connecting-nuts-m6-10-pack/4720g


[Edited to fix the broken link: GrahamM - Moderator]

I did consider the connector nuts at the time, but preferred the idea I went for in the end, in using a regular stainless nut to hold the header in place, with the dome nut covering the small amount of exposed thread
that remained with no fear of it bottoming out, purely acting to seal the end of the stud from the elements. Peace of mind more than anything else, as any job involving exhaust studs usually doesn’t go as well as expected..

[returning rider]

i will second the do not touch the studs i have 4 broken off hence why bike is off the road possibly for good.


The studs are very weak and corrode like mad if you can get the nuts off great if not cut slots in the nuts open them up as getting the studs out is pain in the ass big time.


My bike has stainless manifold, great but the ham fisted way it was fitted wrecked the studs.


As said get the connector bolts lots of thread to grip and do not over tighten the studs are made of cheese.

[butthead]

Leave the studs alone, count your blessings, and buy a lottery ticket

    most definitely !