? about installing aftermarket exhaust, 79 XS11

[mrhammer2u]

I received the Mac 4-2 and mounted them up....did not tighten all bolts yet. Do I have to torque the header bolts? Or just tighten them? I did a search but cannot find this info.

ALSO,....the stock header bolts were not long enough. I had to buy a set of Honda bolts of the same thread but about 3/4" longer so I could get the Mac header flange on. Anyone else have this issue?

Thanks!

[IanDMacDonald]

Just an FYI, removing exhaust systems on these bikes is a breeze, installing them will have the most devout throw some curse word combos out there that u've never heard in ur life! My bike came with Mac's, so I cannot attest to what the original stud length is (there are threads on it here). However, if u were lucky enough to change all eight studs without issue, give urself a HUGE pat on the back, as ur certainly lucky.

Don't worry about torque specs on those, as anything too tight, and you may break something. And, the torque spec may be for the original studs, can't attest to your new stud material. I'd crank 'em down to where ur comfortable, start the bike and let it get operating temp, listen for leaks, then toghten them some more. You don't need to Popeye them tight, just so they no-longer turn.

[BA80]

Those studs should have been long enough to get them started. Did you put new gaskets in? The gaskets will crush as you tighten them.

Tighten them until the nuts won't turn any more but like Ian said, you don't need to eat a can of spinach first.

Ride it a while and check them again. I have a Mack 4 into 2 on mine and I just check them a couple times a year.

If you can use the shorter studs you can put some chrome acorn nuts on there and they look a lot better.

[TopCatGr58]

Hey Hammer,

As has been mentioned, these use header gaskets. After many years, they get crushed, and pressed firmly into the head so that they can look like part of the head. Then when folks go to put new pipes on, they put another set of gaskets in, and this then causes the pipes to stick out farther from the head...sometimes this can cause the header bolts to appear to be too short!

SO....my question is did you check and remove the OLD exhaust gaskets, or did you just pull the pipes, put new gaskets on and try to fit the pipes when you found that the studs seemed too short!?

I hate to say it, but you probably should pull the pipes, and then take a flat screwdriver and try to see if you see what looks like an extra LIP inside the exhaust port, take a light hammer and tap the screwdriver across the port under the "lip" and then try prying. The gasket is relatively soft sandwiched metal and will come loose relatively easily. The head material itself will not move, so no worries about damaging it with the screwdriver.

IF you find the old gaskets, then you will now have too long exhaust studs, and so you will then have choices....like using washers to take up the extra length, along with using a crown nut for aesthetics!?

T.C.

[mrhammer2u]

thanks for all the feedback. I'll take a look and see if there's already gaskets in there. my buddy is a mechanic so he had the tools to take those studs off. It was a breeze except for a couple bolts where was really close to the header tube.

[IanDMacDonald]

Yeah, even with a stud tool, 35 years takes it's toll on those header studs. Congrats on a successful removal.

[mrhammer2u]

so I'm an idiot...I pulled the header off and there were gaskets already in there. they were so black I didn't even notice them. now the studs I have in there are too long and I can't tighten the nuts all the way down. off to Home Depot for some washers!

thanks to the forum for helping me out with this.

[IanDMacDonald]

You could put shorter studs back in . . .

[mjpxs11sh]

+

youre not an idiot, this is how you learn and at times the hard way. this is the purpose of the xs11 forum, experienced solutions for xs11 owners. great forum with fantastic members. thanx to all

[MaximPhil]

I used stainless coupler nuts on mine, then the longer stud is not an issue.
Torque 14.5 ft/lb per the manual.
Phil

[donebysunday]

When you start to tighten the nuts down on the studs count the number of turns from the first thread grip on each to keep them even.

I received the Mac 4-2 and mounted them up....did not tighten all bolts yet. Do I have to torque the header bolts? Or just tighten them? I did a search but cannot find this info.

ALSO,....the stock header bolts were not long enough. I had to buy a set of Honda bolts of the same thread but about 3/4" longer so I could get the Mac header flange on. Anyone else have this issue?

Thanks!

[James England]

Hey Hammer,

As has been mentioned, these use header gaskets. After many years, they get crushed, and pressed firmly into the head so that they can look like part of the head. Then when folks go to put new pipes on, they put another set of gaskets in, and this then causes the pipes to stick out farther from the head...

Excellent diagnosis, doctor...

[WMarshy]

Since you aready put the longer studs in, you could just keep both gaskets in as long as your not getting leakby and you dont bottom out the nuts if the gasket continues to crush... vs using washers... there is no right or wrong, just what does and doesnt work.

[mrhammer2u]

end of story,....

So,....today I tightened down all the nuts and bolts and she purrs like a kitten! No need to rejet or tweak idle screw.

To recap for those having similar issue/future knowledge:
- Always check to see if there are gaskets already in the head. Otherwise you double up on gaskets and studs too short. This was my 1st mistake
- I installed longer studs (prior to learning my mistake) and the factory nuts would not go on all the way. So I used a washer and lock washer along with stainless acorn nuts (for looks) and it worked fine.
- Tightened everything down and she purred like a kitten.

This is all regarding swapping out xs11 special exhasust for the Mac 4-2 turnout exhaust. Seems like a direct bolt on,....when you do it right from the beginning...