Exhaust stud Question.

[Bry]

Ok,

I know there's some mechanical background here, just hunting for a bit of advice please.

Working on the toy bike and I've gone to fit the new stainless headers because, well, the English lifestyle it led has screwed anything metal on it!

I have got to replace 6 of the 8 exhaust studs, I'm trying to find out what is the best way to fit? Reading the net, Some suggest Loctite, others just Kopa-Kote wind in until bottoms and then to tighten 1/2 turn.

Any suggestions? (other than to buy another bike.. )

[thumper]

Hi Bry
You havent mentioned which bike, so I cant make a comment however as a generalisation you can use loctite(I use blue) on the head end of the stud but its not always done as some say the heat at the stud is sufficient over time to break down loctite. For me this is more to reduce corrosion between the alloy and the stud. Different bikes use different metals - I have seen s/s, iron and copper coated iron exhaust studs. If you have coated studs you dont need corrosion protection. Generally you must always use anti seize compound on the nut end to prevent the nut from corroding onto the stud (unless you have copper nuts). You should also do this on a yearly basis - I know most people dont but thats life.
Cheers

[Bry]

Ok, ta, it's a CBR900RR Alloy head, ordered all the replacement studs, I'll do all 8 while I am there!

I suppose it doesn't matter that it's not a BM, hell have you seen the selection at the breakfasts?

[boomer61]

Use the loctite Anti Sieze as its nickle based and works to a higher temp than Copper Kote.
The manual should give a torque setting, if not a stud supplier should be able to give you settings but stipulate you are doing it in an alloy metal not steel as they may give you a steel setting and them you strip the threads.
Replace the nuts and studs as a unit, dont use old nuts on new studs.

[Bry]

Thanx, on it.

I ordered new nuts anyhow, not that I had a choice, only two would come off the damn studs in the first place. Book says 9 ft/lb.

On a side note, handy little calc here..

http://www.boltscience.com/pages/convert.htm

[boomer61]

The XR 600 book settting is 13 ft/lb or 17nm for exhaust stud nuts so in the ball park given the sizes may be diffrent