salmon_slayer06 Posted May 22, 2016 Report Posted May 22, 2016 421 serval dune/play port 4 mm crank t5s Keihn carbs. Pingel fuel valve + 4 timing. 70 degree temps riding at 1200 foot elevation noss cool head 93 octane domes. I started at 170 main 62 pilot needle in middle and that was at lower elevation and 30-40 degree temps. Came up north higher elevation and 70-80 degrees now. Changed jets to 62 pilot main is at 162 needle in middle. I also tried 58 pilot and 168 main but was fouling the plugs but seemed to be lean at 1/4 throttle with a hesitation when into the throttle. Doing another day of tuning I don't want to ruin the motor. I don't have any way of plug chopping just going by the color of the ceramic that I can see. Should I be ball park with 62/162 needle in middle? Quote
salmon_slayer06 Posted May 22, 2016 Author Report Posted May 22, 2016 I'm not sure if they are 30 or 35. I tried playing with the jetting today. I do have v 4s also. Currently I have a 68 pilot 160 main with needle maxed out so its richer. Couldn't get a 65 pilot. 160 main I think is too lean. Taking it home to do a plug chop and go from there. Quote
LaegerEliminator Posted May 22, 2016 Report Posted May 22, 2016 I'm not sure if they are 30 or 35. I tried playing with the jetting today. I do have v 4s also. Currently I have a 68 pilot 160 main with needle maxed out so its richer. Couldn't get a 65 pilot. 160 main I think is too lean. Taking it home to do a plug chop and go from there.You need to determine which size carbs you have. I'm pretty certain your pilot is too rich. I'm thinking 55 or 58 is where you should be with 35 pwk's. Where are your air screws set at? Quote
salmon_slayer06 Posted May 23, 2016 Author Report Posted May 23, 2016 1 1/2 turns out. I'm going back to my original jet set up after I installed the new motor which is 62 pilot, 172 main needle in middle and do a plug chop. it seemed to run decent than but that is on cement not loose sand. Quote
salmon_slayer06 Posted May 23, 2016 Author Report Posted May 23, 2016 Changing jets is a 1-2 hour ordeal. Try doing it at the trail head parking lot with guys ripping by on quads and dirt bikes. Quote
Surfrjag Posted May 23, 2016 Report Posted May 23, 2016 I never herd of anyone using pilots that big.. leakdown test? Pic of carbs.. size is important i dont care what girls say.. 1 Quote
LaegerEliminator Posted May 23, 2016 Report Posted May 23, 2016 Changing jets is a 1-2 hour ordeal. Try doing it at the trail head parking lot with guys ripping by on quads and dirt bikes.Are you running an air box? It shouldn't take that long to change jets. Do you know what needles you're running? Quote
salmon_slayer06 Posted May 23, 2016 Author Report Posted May 23, 2016 Yes stock air box no lid. Stock boots. It's a tight fit. I'm just afraid of leaning it too much. 58 sounds good. I'll be double checking carb size when I take it apart later today. Shooting to have it dialed in for the weekend. Quote
salmon_slayer06 Posted May 23, 2016 Author Report Posted May 23, 2016 Are you running an air box? It shouldn't take that long to change jets. Do you know what needles you're running? Don't know what needles. Will check on that also. Quote
salmon_slayer06 Posted June 1, 2016 Author Report Posted June 1, 2016 Got it dialed in. 58 pilot, 170 main needle in the middle. Very happy with the power. Put roughly 30 hours on it and 20-30 gallons of fuel. Tire wear is definitely an issue now. Quote
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