just ordered a new (4 to 1) exhaust...(questions)

[ERM83]

got a MAC 4 to 1 canister exhaust to replace my now defunct current one. I was riding a couple nights ago, and my friggin' left muffler fell off somehow?! Don't know how...had everything tightened up very well. Anyway, said muffler was one of the MAC 4-2 tapered exhaust systems.

Since I'm switching to the 4-1, I have a few questions. I haven't taken the exhaust off this bike ever...took the one off my 79' (which you all graciously gave me advice on working on), but I can't remember if it has crush-gaskets for the header pipes??

Another thing: I'm using my 79' carbs on the 80' SG. I went up one pilot jet size, and one main jet size (being that the previous owner had the 4-2 exhaust, and the 80' carbs were DONE)...it's been running great since resurrected. I know that the jet guide from here is a bit outdated, so I was wondering...should I go one size up for the mains for the 4-1?? I figure the pilot is okay...the plugs also look fine every time I change them with the current exhaust...

You all are awesome!

Eric

[MaximPhil]

hi ERM83,
You will need new crush gaskets (spiral wound) available from
https://www.partsnmore.com/parts/yamaha/xs1100/?filters[fitting]=custom
be sure you have removed the old ones as they can get so compressed they look like the head.
Be very careful when undoing the nuts as it is easy to break the stud.
soak with PB Blaster or similar penetrating oil before.

Phil

[ERM83]

hi ERM83,
You will need new crush gaskets (spiral wound) available from
https://www.partsnmore.com/parts/yamaha/xs1100/?filters[fitting]=custom
be sure you have removed the old ones as they can get so compressed they look like the head.
Be very careful when undoing the nuts as it is easy to break the stud.
soak with PB Blaster or similar penetrating oil before.

Phil

Thanks, Phil! What are your thoughts on the jetting??

[MaximPhil]

Thanks, Phil! What are your thoughts on the jetting??

Hi ERM83
I share what I know.
You will need a carb Guru as I know nothing about carbs jetting or otherwise

Phil

[DiverRay]

Leave the jetting alone for now. See how it runs, and adjust if you need to later. At most, you MAY need to go up one size on the mains.
DO re-sync the carbs, though. You will need to adjust the carbs for the new header, and it may change the individual carbs just a bit on the idle screws/sync.

[ERM83]

Leave the jetting alone for now. See how it runs, and adjust if you need to later. At most, you MAY need to go up one size on the mains.
DO re-sync the carbs, though. You will need to adjust the carbs for the new header, and it may change the individual carbs just a bit on the idle screws/sync.

Thanks, Ray! Luckily I have and old-school place in town with a BUNCH of XS parts. Got my last jets from there!