GS400E upgrade

[RoChEsTeR]

Hi! I'm restoring my GS400E and I wonder if there's a way I could make it a bit faster! I'd like to have more acceleration and maybe top-end speed also...for now I have to rebuild the carbs as I had a sticky choke problem last summer...maybe rejetting would help?
I bought this bike for 400$ last year and want to have it running like new for the spring with a new paint and miscellanous parts changed and of course more power if possible. What would be the best "upgrade" to do (don't tell me to buy another bike!) to achieve that?
Thanks!

[first timer]

if you got the money you can do anything. get some custom oversized cosworth pistons ($250 a pop?), port the head, accel coils, two bigger and newer dirt bike carbs. you get the idea.. i think you are stuck with very little you can do, i don't even think they have a jet kit for a 400? check dyna jets website. for now learn to ride the bike well and learn it's power band. and be happy with it. maybe go down a tooth on the front sprocket. it will give you quicker accel but lower top speed.

-ryan