Don't wanna type too much, too high and lazy in this awesome pool n mopeds day.
This is "the boner"
Adding switchable volume to the header can give you the lows you could use when running a high rpm pipe or timings. Similar to the v-tacs system some scooter used.
Just used some 3/4 black pipe, a 90deg reducer to go to 1/2 where it mounts to the header so it will be header size-ish.
I'm adding a butterfly valve near the base of the boner tomorrow. So I can kick it open when I'm starting, then close for fuckin hold on action!
Just climbed hills at 5 or 6k I could NEVER climb before except at 9k.
Amazing! Now I can get a low clutch stall and still rip up to 12or 13k.
Just have to shorten the main pipe now a few inches.