Carb jetting trouble

[blaster_joe]

alright i just installed my new top end bored 68mm by kor wiseco piston and broke it in now to start tuning the carb the pilot jet is a 27.5 main is 290 and needle is on the fourth notch?(second from top)and it wont idle unless the air/idle screw is 3.5 turns out it runs good from 0-1/2 throttle it wheelies but once i pass 1/2 throttle it drops, when i took the carb apart it had a 310main and 30 pilot on 3rd notch on needle i counted 3.5 turns with the idle/air screw but with that setup it is extremely rich and underpowered the mods on it right now are 68mm piston, paul turner exhaust system, uni air, and no air box lid so i need some suggestions on the main jet and why the air/idle screw is so far out,



thanks joe

 

[2slow]

hmm maybe lower your needle down one and see if that helps. im no pro but imo think that what it mights be and depending on your elavation id say 270-300 in jet sizes start big and work your way down!

 

[98blaster+4]

call ken bro!!! what carb are you running?? stock pilot in a stock carb is 32.5

what does it do when it falls off at 1/2 throttle?


do you like to read??? i hope so!!
http://www.blasterforum.com/engine-13/copy-how-jet-article-link-excellent-site-17371/

 

[dbowhntr]

You need at least a 32.5 pilot, 35 may be needed. The more turns out means you need a larger pilot. My 32.5 is too lean with a kor ported motor and toomey pipe. That was with a stock carb. How are you adjusting the pilot? turn out until the max rpm is reached. Then adjust the idle with the idle screw not the pilot screw.

 

[blaster_joe]

thanks i will read that thread the pilot is good it was a 30 but i dropped it to a 27.5 cause it was running to fat 0-1/2 throttle is great just past half throttle i took the 290 main out and dropped int the 300 it runs better so i might go higher on the main

its not a kor port he just bored it to 68mm