karz im not an expert at this but i made my stock carb work by drilling out the main jet and pilot jet and got lucky the first time. it was a little rich. but you can buy alcohol carbs. but on a scrambler you need a fuel pump cause you will use twise as much fuel. go to ct racing and get on there alcohol tip sheet it is very helpful.

 

you have to run special reeds. I got mine from FTZ racing, run klots bean oil.I have a ftz mukuni 39MM booster alky carb, worked great want to buy it??? still in great shape have some jets set up for it probly the rite ones too. I also have a nice crome drag pipe with silincer( out of frame) and a ftz msd hi power ignition set up, dont need this stuff cause im runnig a 500 now make me an offer!!!!

 

so is your bike a true 500R?? Or is it just a cr500 motor in your frame?

 

I would go with a lectron alky carb w/adjustable powerjet. Carb is easy to set up and tune and has great throttle response. Probably one of the most preferred carbs on the market.