Lunchbox, jets and exhaust upgrade

[TheDrunknmonky]

I think this should be an easy one, but I want the experts opinions anyway..  If I change any one of these things, do the other 2 need to be done also?  What will happen, for instance, if I upgrade to a lunchbox and don't re-jet, or if i re-jet, but don't change intake, etc?  Based on what I'm finding, I'm thinking that these things have to be done together and that doing one by itself would hinder performance more than help it.  Input appreciated.  Thanks peeps!

[dgyver]

A rejet is needed when increasing the air flow, otherwise a lean condition will occur. Changing jets is simple and cheap.

[TheDrunknmonky]

I agree that a re-jet and intake are inexpensive upgrades and those are the 2 I'm planning on doing first.  My concern is not upgrading the exhaust at the same time.  Am I  going to create too much back pressure, or maybe not enough exhaust flow?  Is it possible to drill out the muffler, as opposed to replacing it?

[galahs]

You'll be fine if you keep using the stock exhaust. 

[gsJack]

As I recall the earlier 89-00 pre 3 circuit carbs were jetted much leaner here in the US than they were around the rest of the world.  Common practice was to change US EPA jetted bikes to same size jets as used abroad.

[Mandres]

The way I understood it was that people have had a hard time finding a jet combo that works well with the lunchbox filter and the stock exhaust.  I'm sure with some patience and trial & error it could be made to work fine though.

[The Buddha]

You can do pipe without leaning it off too much. Lunch box is huge, that will make it very lean.
Pipe you can slide for a while if you put washers or have a little high float set (common on 89-00 as they wear high - them little buggers need fiddling every bloody year).
Cool.
Buddha.

[mach1]

Doing an intake and jets are not that hard  even with stock exhaust hell even a slipon can rhe header restrick the f%$k out of the sxhaust. Doing a slipon only will be fine I did it and seen no change. Doin a rejet only is great. Doing the intake alone bad idead. Leaving the bike stock and ride and have fun really easy.

[simoniz]

You'll be fine if you keep using the stock exhaust. 

+1 on that, that is what I am running on mine.

[ke7syv]

Yeah true you can run a stock exhaust but you'll need to up the jets AGAIN after you change the muffler. Right?

[dgyver]

Yeah true you can run a stock exhaust but you'll need to up the jets AGAIN after you change the muffler. Right?

Correct. Jets are only $5-10 pair.