No choke, no run

11 replies to this topic
  • desmo900

Posted July 07, 2004 - 04:19 PM


Hello, I have now finished uncorking my bike, jetting, carb. boot, airbox, and drilled out the pipe. Unfortunatly it still will not run unless the choke is ON at least half way. Jetting is: 170 main, 68s pilot, 53 needle at 3rd position. Im at near sea level and I have adjusted the pilot screw to the highest rpm. and then readjusted the idle to 1400rpm

It runs great, but something must still be wrong.

Any help would be apprceiated.

  • frankstr

Posted July 08, 2004 - 12:32 PM


I dunno,but it sounds like it wants more fuel,but technicaly it don't need it. Mine is jetted one down from 170 fmf Q and has no prob. Try turning up idle some more and let it warm up,then no choke and adjust idle.
Idle mixture screw should be 1 1/1 to 21/4 turns in that range,mine is about 1 3/4 turns out.
Is carb. clean inside?? Good fuel flow?? :thumbsup:

  • Hamish

Posted July 09, 2004 - 02:20 AM


sounds like you have a bad air leak. I use an old fork oil bottle filled with pertrol and carefully spray fuel around the intake manifold joins. If there is a leak, it will suck the fuel into the engine causing it to run rough, then you will know where the leak is. Not sure about your procedure for setting the idle mixture either. generally speaking higher rpm=leaner mixture.

  • desmo900

Posted July 09, 2004 - 05:55 AM


Thank you for the suggestions. The carb. is very clean inside and it had this problem before I rejetted.
I'll try the idle mixture settings again.
And try the air leak check that was mentioned
I have searched this group and the jetting group and have not found any one with a simular problem, I guess im just special :thumbsup:

  • desmo900

Posted July 10, 2004 - 05:20 PM


Howdy ya'll. I still have the Choke problem. If I turn off the choke the motor dies instantly. I have re-cleaned the inside of the carb. checked the rubber boots for good fit, reset the idle and mixture all with no change. Its like the choke is connected to the kill switch.
My local honda dealer has no advice so you guys are my last hope. Any suggestions? :thumbsup:

  • Hamish

Posted July 11, 2004 - 01:49 AM


did u check for air leaks with petrol?
From what you've typed, it sounds like the problem started when you rejetted the carby. I'd check all the parts that removed from the carby. You didnt do something silly like leave an air jet out? or maybe get 2 jets in the wrong holes? Did you adjust the float level? If the float level was very very low you may get this problem. Have you tried riding the bike? I'd be intrested to know if it goes ok when you ride it with the choke out. Also I'd check the obvious like needle and seat and fuel supply

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  • JetPilot

Posted July 11, 2004 - 02:28 AM


He already stated he had this problem BEFORE he rejetted his carburator

The carb. is very clean inside and it had this problem before I rejetted.

Maybe the air leak is caused by something that went wrong internal to your carb and not obvious from the outside....

  • desmo900

Posted July 15, 2004 - 09:18 PM


I would like you to consider my name for the stupid newbie of the year award

I was flipping the choke lever the wrong way.

the only thing wrong with the bike is its owner.. Thanks for trying to help..

  • JackAttack

Posted July 15, 2004 - 09:27 PM


I would like you to consider my name for the stupid newbie of the year award


Every year I try to win that award and it looks like I'll come in second again. :thumbsup:

I'm not worried though.......there is still time........................ :devil: :awww: :lol:

  • Hamish

Posted July 16, 2004 - 01:33 AM


I was having trouble imagining what could have caused your reported fault. At least it goes now :thumbsup:

  • TimBrp

Posted July 16, 2004 - 01:40 AM


This is funny, I hate to laugh at yah. :thumbsup: Ride on, at least now your BP has come down.

  • BoZerk

Posted July 16, 2004 - 11:27 AM


:thumbsup: :devil: :awww: :lol: :D

That's funny! I was gonna ask if you had the lever down and not up but didn't want to insult you.

Don't worry, you're not the first, I've seen the same thing here before.

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