Serowbot wrote on 07/28/10 at 20:14:01:A good indicator of overall jetting is the weather...if popping/backfiring increases on humid days, or at higher elevation, that indicates rich....less popping at those times indicates lean.
I've noticed no correlation between weather and backfiring. It could be because of my proximity to Lake Ontario, it's always humid.
Serowbot wrote on 07/28/10 at 20:14:01:To test the main, accelerate from 30 or 40 mph, in 4th or 5th gear at full throttle for several seconds, then reduce throttle by about 1/8,...if power increases for a second, you are lean on the main jet. Go up one jet size and test again.
I've tried this several times last summer, with jets 145, 150, 152.5 and 155. I'll see if I can find my posts from that time period and link to them.
I've never noticed any change when backing off the throttle.
I don't know if I'm doing it wrong (not waiting long enough, waiting too long, backing off to far, not backing off far enough, whatever) or if there's no response or if I'm incompetent.
-D. Dwarf