i need help with my main jet, my pilots fine, the last 1/4 of my engines power is blah, not there, chugs, and lags, its a 1980 YZ 250 done .051 over, the main jets a 370. now i beleive its too rich. any others input? its a huge mikuni carb
jetting help, yz 250
- Thread starter ckjohneh
- Start date
CK, I feel for you, but wouldn't this be a better question for a dirtbike forum?
That said, yeah a 370 Mikuni jet sounds a bit large (although I'm not that strong on Mikunis), but you really need to add more information. What size carb are you talking? How does your plug look? Have you read the carb tuning guides on this Forum? They are pretty good.
That said, yeah a 370 Mikuni jet sounds a bit large (although I'm not that strong on Mikunis), but you really need to add more information. What size carb are you talking? How does your plug look? Have you read the carb tuning guides on this Forum? They are pretty good.
no i just thought id ask on here, like its had the bore done to it so its gonna want more fuel but i think someones been tinkering with it already the plugs blacky brown. too rich.
Yep, that sounds kinda rich. I've been playing with jetting for a couple months now and it seems to just take time. There is no magic, one-size-fits-all answer. Buy some jets and try em out.
As a pure shot in the dark, I'd prob step down to a 300 and see what the plug looks like.
As a pure shot in the dark, I'd prob step down to a 300 and see what the plug looks like.
