Stumped!!! CRF80 Won't Run w/o Choke
  • jl0295
    Posts: 1
    Joined: Wed Dec 04, 2019 6:03 pm

    Stumped!!! CRF80 Won't Run w/o Choke

    by jl0295 » Wed Dec 04, 2019 6:11 pm

    Have a 2004 CRF80 in great shape. It starts immediately and runs as long as the choke is on. As soon as the choke is turned off it dies.

    I have cleaned the entire carb (2x) and installed a carb kit with new gaskets and new jets (#95 pilot jet / #35 main jet). I have adjusted the fuel mixture screw multiple times from 1.5 to 2.75 turns out with no change regardless of adjustment.

    There is also no change when I lever the choke - it's either all or nothing. The bike starts and runs at high RPM when the choke is on from fully, 3/4/, 1/2 or 1/4 of the way open. No change regardless of position. As soon as I turn it completely off the bike dies - even with the throttle pumping or held wide open.

    I have also checked the petcock and verified fuel is freely flowing. I adjusted the valves to spec (.05 MM) and have checked for intake manifold and vacuum leaks. None can be found. I am 100% sure this is not a clogged carb or pilot jet problem. The carb is clean and all jets are new.

    Am I missing something else?
  • Aussiecrf230
    Posts: 1864
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: Stumped!!! CRF80 Won't Run w/o Choke

    by Aussiecrf230 » Wed Dec 04, 2019 6:51 pm

    Hi and welcome to the site.

    When the lever is down the choke is off.
    Is that your understanding?

    I only ask because I have had people before thinking it was the other way around.

    How long have you had the bike?
    Is this only a new problem?
    How old is the fuel?

    Have you done any work to the bike just before it started playing up?

    The lot of questions I know but it gives everyone an idea where things are at to help diagnose the problem.

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas

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