View Single Post
Old 08-20-2008, 09:11 PM
misteright1_99's Avatar
misteright1_99 misteright1_99 is offline
Motorized Bicycle Elite Member
Join Date: Mar 2008
Location: Treasure Coast, Florida
Posts: 716
Default Re: Need advice tuning PHBG carby

I believe your jet is too small at WOT, and it is too big at mid range with not enough adjustment in the needle. I just got done jetting a 18mm mikuni, and I ran into the same problem. I first tried notching the needle one more at the top, and that almost did it, but eventually had to make the slide cutaway larger to allow more air at low and midrange. I am not familar with your carb, but they all work the same. If the slide is round the cutaway is on the air filter side, and usually will have material removed from 1.0mm to 3.0mm, mine was a 1.0 and I removed 1.0mm to make it a 2.0 and then I was able to move the clip back down because I know have more airflow. You could also try a fatter needle if avail., for less fuel at low RPM.
Reply With Quote