February 6, 201115 yr Hi all, Just fitted a set of reeds to my 2010 250 after giving up hope of ever getting it to run smoothly like me old gasser!! Initial results were fine, but started to run rich, adjusted needle and airscrew but do I need to change jets. Running a 45 pilot as instructed by Beta UK. Any help would be greatly appreciated.
February 6, 201115 yr Typically yes, Boyesen reeds nearly always make the bike richer across the range. Often you'll need to go one or two sizes leaner on the main jet, and perhaps one leaner on the pilot. However, it's often close enough after you lean the main that you can get the bottom in the ballpark with air-screw adjustments only. Curious though as to why you didn't find the bike "smooth" by that do you mean that you found the power to be abrupt at a certain point in the powerband? Asking 'cause I'm considering buying a new bike and a 250 Evo is on my short list.
February 6, 201115 yr i have not fitted boysens to my 10 evo or my 08 rev 3 but did to my 05 rev3. I have to say that with some careful setting up i have found the later bikes to be smooth off the bottom end anyway. did you notice your carburation was wrong as soon as you fitted the reeds, or has it got progressivly worse? only wondering because if its getting worse over time its probably not due to the reeds. Cheers Paul
February 7, 201115 yr I have the 09 290 EVO with the Boyeson #112 reeds installed. I ride at 7000' and up. My carb is set stock except for the needle clip moved to the 4th position. The floats have also been lowered some. I guess thats a usual Beta mod though. The motor seems to run very smooth. I did try a #45 pilot once but the bottom end torque sufferd so i went back to the #48 pilot. I think the stock pilot is #48 and the main is #120. Edited February 7, 201115 yr by Liviob
February 7, 201115 yr Author It is hard to explain but here goes "After running the bike in I found that the bottom end was not smooth off the throttle and the engine had roll on like my old 4RT, changed to a 45 pilot as instructed by JLB which made it better but still not crisp and still coughs a few beats until it settles back into idle. I've since been told this is due to the flywheel weight which I am in the process of removing. The needle clip is 3 off the bottom and the airscrew is approx. 3/4 turn out."
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