Greetings from NC.
Does anyone have an extra pair of stock RS 250 carbs for sale? I had mine bored by MotoTek (from 34mm to 35.5mm) at the same time that the motor was modified by Stan Stephens (www.stanstephens.com/rgv.htm) to 300cc. Ever since, the bike has not run as strong as it did when it was a stock 250 (Arrow chambers and holes in air box). After spending a lot of time trying umpteen different jetting combinations at the track - none of which yielded good power - I suspect the problem may lie with the bored carbs.
In the process of trying to get this thing to run correctly I managed to ruin a piston. Mr. Stephens has a proprietary setup with Wiseco so I had to purchase the replacement from him. All I can say is he thinks very highly of his pistons...hold on to your wallet! The price is out of line, especially considering the nature of a two stroke and their need for new pistons from time to time.
If I can find some stock carbs and they make this bike run right, then all will be well until rebuild time. At that point, or if the carbs don't fix the problem, then I will probably abandon the 300cc motor as a failed experiment and look for a stock motor to purchase.
Oh....if only I had my strong running, dependable original 250 back again!