Zip_Racer_7
thegr8one
I have an unmodified runner sp 50 which came with a 17.5mm carb. When i got the bike it had a 53 main jet in it, 6.4 gram rollers, and the air mix screw was 1/2 a turn out. Since i have lightened up the rollers to 5.7g, changed the main jet to 75 and the air mix screw is at 2 1/2 turns out, and the clip is at the top of the pin (leanest). The low end and mid range is very clean, but the top end is much to be desired at full throttle the bike is slower than the original settings. Does anyone have any ideas on this??