Bobfarmer6@cs.com wrote:
 
I have a 99-ZX9R">

Question: Bobfarmer6@cs.com wrote:   I have a 99-ZX9R, your Ti. needles, BMC filter, 6 degree advancer, Akrapovic system. I have a lean condition at part throttle high & low speed. The bike pulls clean & hard from low RPM to red line at full throttle. I have 42 pilot jets, 3 1/2 turns out on screws. I have it a little rich at idle but that helped the lean spot a little. The only adjustment that seems to make the lean spot better is to richen the float. I have the float set at 11-1/2 MM. What is the limit on the setting 10mm,9mm?? I had everything set OK until I put the 6 deg advancer on. That's when I got the lean spot & have been trying everything to get it back. I don't want to give up the advancer because I got better low end & 2-1/2 HP on the dyno. Main jets are 158 & 160, needle is all the way down -Clip at the top. I have had main jets ,needles, float up & down . I was going to set the float at 10mm. What do you think? Answer: It's not real common on other bikes to have the +6 advance hurt cruise UNLESS it was too far retarded and the stock curve didn't allow enough time for the delivered fuel to burn. Advancing the timing to where there's enough time to burn all the fuel (as compared with not enough time to burn the supplied fuel) may require additional fuel. That's the bad news (you aren't done tuning!). The good news is that, now that you have better timing - after you add additional fuel, you will be rewarded with better power and response than you could ever get with the more retarded, stock settings, as a rule. If opening the fuel screws helped the cruise, but hurts the idle, I'd try #45 pj's and readjust the mixture screws for best idle again. Raising the fuel level seems like an OK method to richen the cruise - BUT - the fuel level should be set for BEST full throttle / 3k performance primarily. It possible that the fuel level is too low (lean) now? Highest fuel level (smallest float height measurement)- it's a mechanical limit - brake hard to a stop with the clutch in and no throttle. If the bike stumbles and dies when you stop because fuel sloshed forward and up through the needle jet and into the bore of the carb - well, there you go - - whatever it's set at - it's too high. I haven't explored the higher fuel levels that you are talking about. Have you tried larger main jets?? Maybe the mains are too small. That will lean out the cruise, too. Use the main jet that produces the best topend on an EC997 Eddy Current Dyno, on the track or any other safe place. A dj dyno is not a good way to select the best main jet due to the short loading time that the inertia dynos apply. Marc