carb. curious

cmblaster

New Member
Dec 14, 2012
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sevierville tennessee
I am kinda stuck. I am running a 240 kit with a 3 mm stroker and full fmf exhaust with stock carb. I cant get my jetting right. I was running a 340 main and it was running really rich. So i went down to a 330 and now i am really lean and it wont stay running unless i feather the throttle. I have adjusted the needle with both jets and cant seem to get it running right. Any suggestions would be greatly appreciated.
 
a 240bbk stroker is one time i suggest a bigger carb than stock.
are you running an airbox or pod filter ?


1. it must be proven leak proof with a leakdown tester before any jetting can be done.


2. you must start at the bottom and work up for jetting.


3. adjust the floats
http://www.blasterforum.com/carburetor-138/float-heights-how-adjust-them-50565/


4. adjust the airscrew/pilot jet
http://www.blasterforum.com/carburetor-138/adjusting-your-airscrew-pilot-jet-51060/


5. richen the needle till it falls on its face then back down 1 clip position.


6. plug chop the main jet
http://www.blasterforum.com/do-yourself-20/how-plug-chop-38674/
 
I am running the pilot jet that came with the 240 kit, also airbox. What is a good pressure to run the leak down test at. What would be a good size to go up to for a larger carb.
 
7psi max. for leakdown tests
2 stroke leakdown testers must attach to the intake, not the spark plug hole like a 4 stroke.

i always suggest at least a 32-35 for BBK's but my opinion is debatable.

you can't just run any 'ol pilot anyone suggests for you, you must tune the airscrew and pilot as described in the link above for your exact bike, location, temps, elevation ect.
 


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