I installed a Kerker and K&N pod air filters on my 1975 CB400F. I got it jetted as close as I can with mains, pilots, air screw opening, and jet needle position. I have a lean flat spot between the pilot jet/air screw tuning range, and the needle jet clip position tuning range. When I overjet the mains to the point that my plugs are soot black after a WOT plug chop, the flat spot is gone and my bike pulls from the bottom through the mid range more sweetly than it ever has...I guess I need thinner jet needles. My needles are K18234 (Honda part number 16012-377-004). I have never tuned a carb by changing needles. Should I change just one size at a time? what increments do they come in? Is one size smaller enough of a change that I will feel the difference? What size jet needles do you think I should try? Where can get them (I Googled and failed to find a source myself)?
Mains 88.9
Pilots 38, or 40 (not a dramatic difference between the two when the air screws are set right)
Jet Needle Clip Position 4th from top
Air Screws, 2 1/2 worked best with 38 pilots
There was a post in 2007 "Slide NEEDLE Where to BUY". In a response, Bodi talked about turning down needles. If I had some extra needles, I would definitely try that.
Thanks, DV
Anybody want to borrow some reamers? 0.032" (81.28 Jet), 0.033" (83.82 Jet), 0.035" (88.89 Jet), 0.036" (91.44 Jet), 0.037" (93.98 Jet)...Trade for 90 mains:)
