Serious Engine Performance Q's

[Hi-T]

I've been back and forth between trading the gs up or upgrading and rebuilding the gs this winter...  And I rather build up the gs.  

What can be done to the gs to seriously up the performance on our little motors?? I've already done the exhaust, rejet, filter, suspension, and tires but now want to take it to the next level.  And if I start planning, budgetting and buying now- come December, I should have everything I need to tear down the bike.

The Bike is an 01 and has 17000 miles on it.  I'd like to keep the costs under $1000.

What can be done to the top end and where are the biggest benifits in performance?  (Cams, Pistons, valves, honing, machining, etc).
What can be done on the lower end?
If the biggest benifits come from the top end- should I even worry about touching the lower end??
What can be done to the transmission/clutch?  I think I remember reading recently about removing the fly wheel? What are the best choices for a clutch replacement?

I know we're talking about a gs- but between the payment and insurance I'd rather not move up to a bigger bike yet.  But I would really love to get rid of that 2000-4000 rpm slump and not have to work so hard at chasing down a 600.

Thanks boys and girls-

[davipu]

nos and a turbo, but you will probably need to rejet.

[dgyver]

- Megacycle cams (//www.megacyclecams.com)
- Heavier valve springs
- Neck the valves
- Larger bore pistons 75mm to 79mm
- Mill the head
- Mill the cylinder
- Barnett clutch
- Timing advance

[JamesG]

The transmission is both pretty good and there isn't really any performance gain you can get out of it.

I take it this is a street bike?  So you should leave the counterbalancer, starter, and generator on it. So that just leaves the top end to play with.

I would stay away from radical racing mods. They tend to make motors less friendly when used at usual street pace. Easiest way to increase power is with an ignition advancer and by increasing displacement with an overbore.  After that cleaning up the head with a port job will get you the most improvement. Its cheap to do IF you know what you are doing, but expensive if you have someone good do it for you.  After that you start getting into the murky world of cams, cam timing, and playing with compression, where you will only eek out 1-2 HP per hundreds of  dollars spent.
Going with larger carbs (or flat/round slides) is in there somewhere, but can hurt street drivability, because their jetting can be touchy.

If nothing else, after you've done all this work and turned your nice, civil GS into a cranky 50HP headache, you will feel much better about the decision to get a new bike.

[RoundBall]

what is
- Barnett clutch?

[JamesG]

Barnett is a US company that makes Aftermarket clutch plates, usually heavy duty and arguably better quality.