F 650 gs main fuse

thats a bit too dangerous
dissasemble the main steering pivot sections on the forks
inspect the bolt and bearings yoke for damage
check the shocks while there
replace with new parts

Richard, I would suggest you go with a stage 3 jet kit for improved air flow. Ebay has them for a great deal. I'll post a link. Good luck. ^^
Dynojet Stage 3 Jet Kit For Suzuki GS650 GS 650 1981 1982

The fuses on the F650CS (scarver) are located under the seat.... remove the seat first. Then look up near the RHS area usually covered by the front of the seat and there will be a small black plastic cover over top of the fuse box. Remove the cover to access the fuses.

The CV carbs actually prefer still air from the standard air box, but try the choke at 3000rpm and if it helps then it is lean, raising the needles may help at this rpm. may not need bigger mains unless you also have a sports exhaust
remember that to raise the needles you put the circlips in the lower grooves.

Is it this you are looking for?
http://corne.ygm.co.za/manuals/F650GS_EU.pdf

307 pages to read:)

And this can also help you if you need more assistance:

http://faq.f650.com/main.html

Good luck
Nic