I've been trying to get my hobbit tuned and have been running into some issues getting the lower throttle range dialed in.
It's a 78 PA50i with a DR kit, stock head, proma with polini baffle, PHBG 19 on an MLM intake, boysen dual stage reeds on a PA50ii reed block, upgraded clutch springs, and a camino 6 roller variator with a fast arrow ramp plate and weight set.
The carb has a W7 needle in the second notch from top, a 30 slide, 88 main jet, 40 idle jet, still have the disc in the bowl (consensus seems to be to chuck it), not sure about the atomizer.
It loves running in the mid throttle which is great and it gets up to 30-35mph pretty quickly. I haven't pushed it to the main jet for more than a few seconds at a time as the kit's not broken in yet.
At lower throttle positions I can't get it to not 4-stroke, even with a 40 idle jet and the mixture screw all the way in it just sounds ragged. I tried running a little bit like this to see what the plug looked like and counterintuitively it came out white, so not sure how I could be 4-stroking and running lean? (At mid range the plug looks good)
It's worse if I get into the mid range and gain some speed before coming back down to lower throttle.
Being in Portland people have a tendency to drive slow and I need to be able to ride at low throttle (20mph) without feeling like my engine is going to explode.
The tuning spreadsheet hasn't helped very much but after reading through this thread it sounds like I'm not too far off on the main jet, idle jet, and needle but could the slide be the issue, maybe swap out for a 40 or 50 or is it something else?