Just got a new Airstriker from JDJetting installed on a 2000 rm125. Runs near proper but weak on the choke, only runs the top 1/4 of the rpm range off the choke. I can feather the throttle up to that rpm to run, but any good goose of the gas "under the pipe" just kills it. Idle air screw from 1 1/2 to 2 1/2 turns makes no difference. I think I need to raise the needle. Do I need to change the air jet? Any help would be appreciated.