Need Help also . 2 fast and Furious RM250

I recently bought a 02 RM250 from local racer (over the hill gang) guy weighed probably 250 and had all work done like porting & polishing, head mod etc from Bills racing,has bills pipe,Vforce,etc I am B class MX rider came off YZ250F big bore to 280 which was great but wanted more power so came back to the 2 stroke. Was only gone from 2 strokes for 2 years. This bike is to friggin fast..It dont even know I am sitting on it and I weigh 205. I go off jumps 50ft table or so and when I land and any bump makes me give it gas. I mean a little gas and it wheelies like crazy. woops forget about it!!! This thing is gonna kill me. Trails and hillclimbs no problem. I cant ride it on the track which I like the most? Thinking about flywheel weight but what size should I get?and is that what I need?how do you put flywheel weight on ? bolt on or ?
suggestions? saw someone say about spring on power valve to lessen spring presure? or is it tighten spring pressure?

Help!

thanks for the info guys. Yes tried the sprocket. had 51 on it originally went back to stock 49 no diff or little still to fast! I dont want to go less then stock. Will defintly give the weight a try they have at Stealthy 7,9,11,13 I think I will go with the 9 or 11 cause I like the power just want to tame it a little. it sucks trying to race having to sit on tank and in 5th gear pulls straight up if I get traction.Im used to two strokes as I have a stock ported 01RM250 with pro cuicuit pipe,Vforce,etc and fully ported and polished,big bore 277 LT250R suzuki 2 stroke Quad that I also race flat track. This new bike is just frigin crazy!!! I am faster on the 01 as I can handle bike to most of its potential the 02 is riding me and I am hanging on for dear life.LOL
thanks all for your help.
Casey