philfz600 Posted April 19, 2013 Posted April 19, 2013 bought some K&N clamp on air filters to replace the stock air box that i had on the bike when i bought it. Upped my pilot jet from 30(stock) to 32.5 and main jet from 107.5(stock) to 112.5. I also "shimmed" the needle with some small washers (+2 on each needle). Upon these jet options i noticed the bike ran fine up until 75-85 mph on highway in which at these speeds it would "hickup" or jerk a bit as if it is still starving for fuel??. (at anything over 3/4 or so throttle the bike would stop "jerking" and run perfectly fine (main jet at WOT) if i run the bike at the 75-85 range it will eventually start to lose power and with out moving throttle position the bike would begin to lose speed as if it were fouling plugs? or perhaps overheating? i have tried shimming needle from 0 to 1 to 2 to 3 and even 4 washers on each needle and all positions minus 2 washers would run drastically worse. (50 mph befor acting up) i also seem to be having some issues with the pilot screw settings. i know you want to look for the highest rpm range when idling below 1k but some of the carbs seem to show no increase or decrease in performance. all will shut engine down when seated but one of the carbs (#2 i believe) has its highest rpms showing at only 1/8 turn out. is it normal to drop a pilot jet size on only 1 carb??? this being said i based the carbs screw settings off the color of the plugs at idle. so bike runs best with 32.5 pilot, 112.5 main jet, 2 washer needle raise, and carbs pilot screws set at carb1=3 turns out (tan plug at idle) carb2=2.5 (tan) carb3=1.5 or maybe it was .5? (tan) carb4=1.75 (tan) float high is the manual recomended 22mm (if i recall correctly) other important info: carbs have been bench synced and then synced with the manometer or w/e the proper name is. no known intake boot leaks, idle is regular and does not drop or raise up, also throttle response is good and returns to an idle as it should w/o dropping below or being hung up at any rpms. petcock also performs as it should (iv had this gas tank off a million times:*( (i mention this because iv heard rumors of peoples problems being the petcock?) i guess it could be possible the vacume isnt strong enough to keep a strong flow of fuel threw the lines, and the decrease in speed after long rides could be the lack of fuel in bowls? (petcock struggling to keep up?) (this only explains the dieing after long rides tho.. and i find unlikely) suggestions on what im forgetting or what my problem could be? based on the diagrams, at this throttle range its running on both needle,needle jet, main jet, and pilot jet/screw so i need some guidance on what to try next. may invest in yet another size up on main jet, but i dont recall anyone needing to go up so much on main jet for air filter upgrade alone.
Moderator drewpy Posted April 19, 2013 Moderator Posted April 19, 2013 did you check out what is supplied in the stage 3 jet kit? I think that is the setup for racing with pods
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