BMWPower said:
Does the spacer lose power in a certain part of the power band, or does it just improve the bottom and leave the rest of the power band the way it was?
In my experience it is subtle, but the transition from low to mid is smoother, the bottom end feels stronger, and the top is still there. I run this with a FMF sst pipe and turbine core silencer. I ran with a flywheel weight, but have now taken that off.(Didnt like it). Like I said , I didnt think it did anything till I took it off for ice racing, and after a couplr rides put it right back on(the spacer). It is subtle , but it helps the bottom to mid transition.
I have found that the pipe makes a huge difference on these bikes too. I had a stock pipe,good bottom and mid , NO top. Went with the pro circuit, no bottom HARD hit to mid range and good top. FMF SST little soft on the bottom, GREAT midrange and top. Put 2 stage reeds on , and powervalve spacer, Got alot of my bottom back, smoothed power output, the bike now is like a fast revving 4 stroke.
Unfortunately , I bought a Gorr built KX 144, and now only use the 250 for the ice and play riding,the 144 is my woods bike. The 144 is AMAZING also. If you can do like Bandit and make a spacer up, give it a try , I think you'll be impressed.
Dave