exhaust bolts coming loose

[Steve]

Yes. You have exhaust gaskets. If you look at a fische for your bike it's #4 on the muffler diagram.

For your convenience, here is a link to the Bike Bandit fische.

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[dr_fosg8]

Well I got some new bolts from the local Fastenal store. Lucky to have one of those close by, those 45mm lengths seem to be hard to come by.

Got them installed with a bit of anti-sieze and some new hardened lock washers. They actually seems to torque down better, could have just been my imagination being optimistic though. I will have to see how they do after a couple of rides.

[Zooks]

Whatever you do, don't ever be tempted to over-tighten them to hold them in place. A stripped thread or snapped bolt (in the motor) will be a complete PITA.

[67fire]

Off topic, sort of, I just happened to google search for properties of anti-seize and here is one of the listings:

http://www.sealanddesign.com/category/7/Loctite/page/104/Lubricating/cpage/49/Anti_Seize.aspx

I have always used the C5-Copper on exhaust parts and the Silver on everything else. Only 200 Degrees difference? And, surprised to see that the Silver was over 1000 Degrees!

Eric

[dr_fosg8]

Zooks, that worries me all the time with torquing in cast aluminum. I torqued them to around 150 inch pounds. Which now that I typed it out and thought about it, is 2.5 foot pounds too tight. Should have been 120 inch pounds.

You would think with as much as I have tightened these I would have remembered that

[tkent02]

The problem with using bolts is the wear and tear on the aluminum threads in the head. They are already worn, any more only makes them looser, easier to strip out.
Use studs.

[dr_fosg8]

I did look for studs but could not find anything suitable. Tkent, do you have and measurements for a stud for this application? And a source to get them?

[tkent02]

I did look for studs but could not find anything suitable. Tkent, do you have and measurements for a stud for this application? And a source to get them?

I think they are 8 x 1.25 x whatever length you need for your pipe. A little too long is fine.

I put them in with Blue Locktite, finger tight until it bottoms then back out 1/4 turn. This prevents bottoming the stud in the hole which is bad, it helps put pressure on the threads, helps to strip them out. Ask an aircraft mechanic about this part. Nothing should ever be bottomed out.

Are you using the original pipes with the cast rings or an aftermarket pipe? If the original rings the lockwasher should lock, use a new one as they get hardened with time and heat cycles too.

With most aftermarket pipes the flanges are curved, so a lockwasher won't work well. Then use anti-seize and a locknut, not a Nylock but one where the nut itself is deformed to make it stay on.

I like the copper locknuts used on BMW cars, they withstand the heat a long time and don't rust up. They should also have suitable studs, if you don't find them elsewhere.

http://www.autohausaz.com/search/product.aspx?sid=zixltz552zjft545ehf3aw45&makeid=800003@BMW&modelid=1010822@2002&year=1976&cid=21@Exhaust%20System&gid=5880@Exhaust%20System%20Nuts,%20Bolts,%20Screws,%20Washers

[dr_fosg8]

So basically what I am looking for is a small piece of all-thread to loc-tight into the head?

[tkent02]

So basically what I am looking for is a small piece of all-thread to loc-tight into the head?

No, all thread is soft, get good quality automotive studs. Don't think you could find all thread in the right size anyway.

[dr_fosg8]

Something like this. http://www.fastenal.com/web/products...0349267&ucst=t

[Zooks]

As Tom said, you need proper metric exhaust studs. You may find that some small Japanese or Euro cars have the same size if you can't find bike ones. Go to an auto parts store.

[Zooks]

This pic is from Z power in the UK.



Similar to what you are after.

[Nessism]

Before tightening those exhaust bolts you might want to make sure the muffler hanger bolts are loose; you want to exhaust system to be free and able to float with the position of the head pipes. After the head pipes are snugged down, tighten the muffler hangers back down last.

[Zooks]

Good advice there Ed.