how much approx. do you think

Going from a 220 or 230 to a 290 is a big jump. I would try the 250-270 like mentioned above. To need a 290 you would have to have more mods than you do.
 
first get rid of the 5/16'' spacer.then check your v-force 3 reeds and make sure it has the insert in the middle of it,its call the air guide.I would start out at about a 310 main jet and see how that goes.Also what ratio are you running with your oil gas mix?32/1 or what?
 
ok, you have a reed spacer? vf3's, take the reed cage out, and your spacer, put the spacer over the reed cage and push up on the bottom of the reed cage where the petals are, there might be too much leniency between the spacer and reed cage, you might have broken your reeds, check them out also, because everytime you hit the gas the inertia is pushing the reed set out of the casing, trust me your symptoms are the same as mine, it was very much a pain in the ass