I am running a stock '05 vmax with a k&n, filter kerker exhaust and a dynojet stage 1 kit with 160 mains . When the bike is at 1/4 throttle it was running way lean as soon as it was cracked to full throttle it was really rich 11.1 a/f ratio. It put down 108hp 73tq . After that I came home and lowered the needle jet from the recommended third clip position to the forth to fatten up the low end and it runs strong as hell .I won't get a chance to dyno again until next week. The dyno jet kit recommends 170's with a k&n and full exhaust but it ran like shit with 170 mains the 160's felt alot better but I see alot of you running 155's and getting better numbers any suggestions ??:bang head:
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Turbomark
Active Member
Remember this rule, lean is mean. Due to differences in manufacturing tolerances every bike is going to respond a little differently than the next. There is no such thing as plug and play when it comes to carb tuning. It's time consuming so be patient. The best way to tune the carbs is to creep up on the tune up. Don't just jump right up to the big jet and needle settings because that's what the directions or somebody told you to do. Take your time and try one setting at a time, never do more than one change at a time! The directions with the kit will only get you in the ball park most of the time. Sometimes, they will be right on!
Turbomark
Active Member
From closed throttle to quarter throttle about, you should be able to adjust the idle mixture screws to get it richer. When you say you lowered the needle. Do you mean you lowered the needle into the main jet or raised the needle? You do that by raising or lowering the clip on the needle as you know. Your statement is a little confusing, is why I ask. Did you lower the clip on the needle or raise the clip? Needl settings have the most affect on half to full throttle opening. I suggest you get familiar with the different circuits of the carbs before you start tuning, it makes life a lot easier.
Turbomark
Active Member
There are some excellent carb tuning instructions on this forum, check them out and take your time. There is no instant solution, treat your situation as being unique and you will be successful.
I raised the needle lowering the clip from 3 to 4 and it felt better I actually was able to adjust the carbs while doing dyno pulls I started at 2 1/2 turns out like it said in the kit and it was almost off the chart lean at 1/8 throttle . I went out in 1/2 turn increments twice to try and get part throttle a/f ratio correct. Thats why I changed clip position after I got home from dynoing. I haven't had a chance to check it on the dyno since that adjustment . I'm wondering if I need to go down to a 155 the kit came with 160'165'170 mains.
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