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idling and needle tuning


Derrickc14

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I have no problem with dialing in the main jet. Plug chop and adjust. But, how do you know when to adjust your pilot and needle position. In other words, what are the symptoms/signs that you need to adjust them. I've been searching but can't seem to find to much on this....

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One symptom of the pilot or airscrew is a bogging on take off. The needle can give you a choppy or boggy mid throttle. All of these will have to be adjusted with mods. New pipes, reeds, pods and etc

 

Sometimes needle position has to be adjusted for bogging off idle too

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Derrickc...
You should post all your mods, what carb´s you have and what´s in there now. Elevation and temp will help alot.

This site has plenty of knowledge people who can see easily what´s going on, but before anything, they need to know details.

 

Does it start good? With or without choke? How the idling when motor is warm?

Does it run good/better after half throttle and have issues below that?

 

Anyway... do one adjust at the time and test it with warm motor. Always go rich first if you don´t know if it´s lean or rich. Fouled plugs are cheaper than pistons.

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Gotcha. Thank you! I'm at 300ft asl. Mods are - +4timing, coolhead with 19cc domes around 175 to 180psi, stock cylinders with dune port from F.A.S.T, pods,sb cpi, stock carbs. I'm starting with 30 pilots, 240mains and needle in 4th position.

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I don´t know much, but 240 is way too lean! I would say closer to 300 is a good starting point. Don´t run it with 240! People with more experience can get you closer. I´m only saying where you should be right now.

Needle 3rd or 4th.

Alot of people use 27.5 pilots

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Also if you go riding in low revs half throttle and less you can plug read that also if it's really rich the plugs and end off pipe will be gooee

If the pilot is right the air screw should be between 1/2 a turn to 2 112 turns out with the bike idle smooth and should respond without hesitation after even 1/2 a mini

The jet height wil change your idle mixture so you'll have to reset the air screw

Sand or up hill is best to set needle height as what feels good power on hard flat ground will be to lean on sand by a lot

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  • 2 weeks later...

uhh  ok here is a go..

 

start bike.  you have a carb synch tool right?

 

if you can  synch the carbs AT IDLE to a even point..  if it wont idle at all ever  its got to big a pilot in it..  if it will not die from to low of an air screw setting ( throttle blase height adjustment  NOT the cable adjust on the tops of the cabs, OR the MIXTURE screw in the front/ bottom/ side of the carb...)   its got way to fucking lean a pilot in it.   if this is the case STOP  change the pilot acordingly.  get the bike to IDLE OK FIRST>

 

THEN  use your synch tool to slowly raise the carbs slides up just off idle using the thumb throttle.  get them at a steady setting on your gage at least ONE of them  set this to the SAME on both sides.  you may have to do this repetadly because it is hard to hold the throttle, shove the synch in there, AND adjust the TOP SCREW on the carb tops.  

 

then you need to recheck the pil..................................

 

 

 

oh fuck it  typed this shit to many times already.

 

 

 

go read the jetting page thats pinned pleasse.

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