'83 GS1100E exhaust question

[lehrin]

So I finally had a little (not enuf) time to put the Kerker Meg. header on my bike. I had to go get different bolts to put it on, and on the #1 cylinder I couldn't get the ones I bought to cinch down very well, they get too hard to twist faster than the others, I think I will buy the next shortest size and use that... but that's another story and another post.
A little more background before my question: my mechanic rebuilt my carbs and put #116 main jets in, due to lots of humidity up in my area as well as new gasoline etc. I had been getting mediocre mileage (25 mpg) so I figured the bike was too rich. I read the plugs, they were "rich but OK." Then I put on the header and it blew some black smoke which may have just been collected in the pipe from before I got it; the amount of smoke seemed to reduce as I sat and played with my new beautiful sound... (didn't bother to put in the glass, maybe later... then again maybe not).
Unfortunately, I had to leave town so I didn't get to mess around with it...
So, here are my questions:

1) Could the #116s with stock pipes have caused my poor mileage,
2) Should the pipe alone lean it out enough, or do I need to install a full jet kit (needles, etc.)
3) When enjoying the new sound at various RPMs, there was some popping as the RPMs would fall from high rev, could that be from not having the pipe 100% bolted on? I would say that with those two bolts being too long it was about 95% completely bolted down (enough for me not to worry about starting it up).

Thanks in advance guys.

[Anonymous]

Don't get shorter bolts if they work on the other cylinders. You will strip out the threads with shorter bolts. Get a tap and clean out the threads.

1) Possibly
2) Maybe
3) Could be

Fix the threads witha tap and go from there. While you are at it, clean all the threads on all the cylinders with a tap.

[Anonymous]

Hey, so ya finally put the header on. They sound nice, don't they? 8)
I agree with swanny; next time you're fiddling with the pipe, run a tap through the holes just in case there's metal or slight stripping in the holes to clean them up.
Not sure on the jetting thing. I suppose you'll have to try it for a bit to see how your mileage is after a tank or 2. The header will lean it out but only so far. A full jet kit will give more power but fuel mileage will drop, been there. It is a performance mod after all.
Don't worry too much about the popping, my 750 has its share but its not overly loud. If you sound like 22 shells going off, then I'd worry.

[skip]

the popping is common with a 4 into 1 under de-acceleration . when you put the fiberglass in it will lessen. but you will still have it. the more free flowing the exhaust the more chance for popping unde rde-acceleration