I had a 91RM250 up until the spring of this year. Spent a lot of money getting it n shape in 2000, but it was a solid bike. I wish I had my jetting settings for you, but i sold the bike, manual and all. I know the main jet was a 340, cause i found a receipt for that. not sure about the rest. I had it dyno'd and with the shorty silencer i made, it had 42HP. not bad for an old girl!! visit http://ca.geocities.com/willysrm250 for some pics!
i've tried FMFracing jetting settings on my 02 RM250, and they worked awesome. For your info, they recommend the following for a 91 - 55pilot, 360main, 60 needle with the clip in #3.
as for the bike not responding, my wife's yz80 had a similar issue....her reeds were damaged but more importantly, the silencer tube was crushed from a fall and it wasn't running due to that. I spent so much time on that bike, monkey'd with the carb etc.... then found out it was the silencer causing the headaches.
Hope you get the 91 rolling, it was a fun bike to own.
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