mac exhaust questions

[03svrider]

i have a mac 2 into 1 exhaust i got off of ebay and i finally installed it on my 81 gs450L last night.
1. can i run the bike with the exhaust on without hurting something before i rejet the carbs?
2. also, i put new exhaust gaskets in after getting the old ones out and there are small leaks around where the pipes go into the engine. i tightened the bolts that push the headers into the head but really didn't want to risk stripping them out by tightening them too much as one is a helicoil i installed and the other is just a stud helicoiled in that was there when i bought the bike. will warming the bike up and letting everything get hot, then letting it cool completely (like overnite cuz that b!tch stays warm for awhile!) and then tighten the bolts a little more help seal them up?
3. if the leaks remain and i ride it anyway, is that bad?
4. there is one bracket that came in the parts bag with the system, shaped like a long "L" with a hole on the top of the "L", that seems to have no purpose. anyone know what it's for?
5. i started it up with the baffle out and it is WAY too loud. with the baffle in it sounds like the rudest little bike. i am psyched to finish the little bugger for next spring.


THANKS for any input. hopefully my long list of questions won't deter any answers.

[focus frenzy]

1= depends on how the jetting was before installing the MAC. testing and plug chops will be required.

2= are you sure you go all the old gasket out?

3= it could erode the gaskets and get bigger, need to see how the pipe is sitting on the gasket, (check the squish of the gasket)

4= it is a mounting bracket, if you have it mounted up correctly without it it is then a souvenir.

5= keep the baffle in, you don't want cruiser/ chopper riders complaining to the police about all the noise you are making.

[03svrider]

thanks for the answers. i'm positive i got all the old gasket out too.

[nabrams]

When I had to re-mount the MAC 4-into-1 on my CB750 (the previous owner botched it terribly), it took me several tries to get it right. The pipe has to be sitting "just right" on the gasket and the collar has be surprisingly tight - of course, using a torque wrench to verify that you're not exceeding the spec in the manual will be critical here.
And yes, you definitely want o make sure there are no exhaust leaks at the juncture between the head and the pipe. It has a surprisingly significant effect on performance.