Exhaust header leak,looking for fix tips...

[Guest]

Hi,
One or more of my pipes are leaking a small amount of exhaust on the head. Can these be torqued down(assuming they still move) or would putting in new gaskets be the best fix...? Any tips on removing these bolts? Not sure how long they have been on, probably 10+ years.

Thank you,
Andy

[Grimly]

All you can do is cross your fingers, hit them repeatedly with penetrant before you do anything, give them a heat cycle or two, more penetrant and try to get some movement on them, in or out.
Assuming you get them loose, you can try to tighten the leaky ones up, as it doesn't take much to cause a blow-by but be careful of over-stressing them. Once the exhaust starts to leak, it's only a matter of time before you have to replace the gasket rings anyway. If you manage to get them all loose, you'd be as well to take the system off and replace all the bolts with stainless studs (and brass nuts, if available) to avoid this common weak spot in the future.
You could try to replace them individually, one at a time, without taking the system off, because if you caught the leak in time, the gaskets might not be past it yet and the bit extra tightening you can put on a stud might be enough to cure the problem for a long time.

[srg]

If you manage to get them all loose, you'd be as well to take the system off and replace all the bolts with stainless studs (and brass nuts, if available) to avoid this common weak spot in the future.

I second this. I got my replacement parts from McMaster:

Metric Zinc-plated Steel Fully Threaded Stud, M8 Size, 50mm Length, 1.25mm Pitch
94595A361 x 8 each

http://www.mcmaster.com/#catalog/120/3174/=snj6tj

Metric Brass Hex Nut, M8 Size, 1.25 Mm Pitch, 13 Mm Width, 6.5 Mm Height
90690A055 x 1 package

http://www.mcmaster.com/#catalog/120/3193/=snj6wk

[ozman]

All you can do is cross your fingers, hit them repeatedly with penetrant before you do anything, give them a heat cycle or two, more penetrant and try to get some movement on them, in or out.
Assuming you get them loose, you can try to tighten the leaky ones up, as it doesn't take much to cause a blow-by but be careful of over-stressing them. Once the exhaust starts to leak, it's only a matter of time before you have to replace the gasket rings anyway. If you manage to get them all loose, you'd be as well to take the system off and replace all the bolts with stainless studs (and brass nuts, if available) to avoid this common weak spot in the future.
You could try to replace them individually, one at a time, without taking the system off, because if you caught the leak in time, the gaskets might not be past it yet and the bit extra tightening you can put on a stud might be enough to cure the problem for a long time.

if your fitting stainless studs or bolts make sure you use a anti seize on them, best use even if your putting the normal bolts back in
on old exhaust gaskets tightening rarely works
i use the nickel anti seize

ozman

[Grimly]

if your fitting stainless studs or bolts make sure you use a anti seize on them, best use even if your putting the normal bolts back in
on old exhaust gaskets tightening rarely works
i use the nickel anti seize

ozman

Deffo to all of that. I've fallen back on Copaslip, but need to get another can of nickel Never-Seez or equivalent.

[Mr.Mom]

Hi,
How do I determine what size etc. of stud to get?

Thanks for all of the tips

[OldVet66]

When you get the bolts out (just be super careful and use a good penetrating oil, work the bolts in and out until they start moving freely), get a small angle pick and remove all the old gaskets. Use two gaskets when you replace them. The flanges on the 4-1 pipes may not sit perfectly parallel to the machined surface in the head and are prone to leak. the second gasket will give them enough compression to seal without bending the ears of the clamps. I have had real good luck with stainless steel Allen head bolts and anti-seize. I remove my 4-1 every year for painting. Removing the bolts with a warm motor is easier after the first time. I have had my exhaust off Three or four times and haven't changed gaskets since I put a fresh set of two in. They seal each time.

[Mr.Mom]

What type of gaskets do you recommend?

Thank you,
Andy

[OldVet66]

I use these. http://www.z1enterprises.com/ShopByC...01010405020805

[Mr.Mom]

Those are the ones in my shopping cart. I just doubled up. Do I need to use a specific torque or will "nice and tight" do?

[ozman]

the standard suzi gaskets are cheap and work fine
i have found 1 ex gasket works fine unless you have a pipe like old vets where the the faces are not parallel
i have bikes with stock pipes and assorted 4 into 1s ( V&H kerker bassini yoshimura premier megacycle transzac) and on none do i have to use 2 gaskets
you need be careful if you use 2 gaskets as the ex bolts dont grip as much thread making them easier to strip if over tightened
when you insert new gaskets put either dobs of grease or silastic on inner surface this will hold the gaskets in place while you fit the pipes
bolts are 8mm metric fine

goodluck and dont forget the anti seize
ozman

[tkent02]

NAPA sells a kit with about ten studs for $8 or so. They even have a little hex on one end so you can hold it while you put the nuts on. I don't use the nuts that come with it, but you could.

[OldVet66]

If the ears on your clamps are bent straighten them out while you have them off. They should be nice and snug but not tight enough to bend the ears. Most 4-1 pipes I see have clamps bent trying to seal leaks with one gasket.

[MK3Brent]

O'Reilly's has a 55mm length M8x1.25 stud kit in one of their aisles. I picked a set up, there are 10 studs and nuts in there. They have a 6mm hex head you can use to drive in to the head.

55mm works for me with my aftermarket exhaust. Might not be the right length for others.

I was having issues with the gaskets like sold from Z1. They didn't quite match up to my tube ID/OD.

Just purchased some of the traditional Cu ring style gaskets. Hope they work better.

A nice trick for these type; you can squash them a little into a slight oval and they'll stay put in the head while you try to mount up the exhaust.

[Mr.Mom]

Well they all came out super easy. 2 of them too easy they broke in the head.