2004 Yamaha 8 horse idle problem

Discussion in 'Outboard Maintenance' started by jcoody, Jun 19, 2011.

  1. jcoody

    jcoody I Love microskiff.com!

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    My 2004 Yamaha 8 horse sat up for a while and I just went through the carb and cleaned it today. It runs great, accept idling. I can play the choke and keep it running at idle speed. It runs great at almost anything above idle and it starts very easily. I can't find any adjustments on the carb though. Anyone know where there may be some adjustments? Or what is wrong with it?
     
  2. Brett

    Brett > PRO STAFF <

    Looks like a fixed jet carb.

    http://www.boats.net/parts/search/Yamaha/Outboard/2004/T8PLHC/CARBURETOR/parts.html

    Everything is functioning except it won't idle
    which means the low speed passages are still dirty.
    Cleaning a carb involves more than just the areas you can see.
    The tiny passages through the carb body have to be clean also
    in order for the carb to allow fuel to be pulled through at the low pressures at idle.
    By manipulating the choke at idle, you're increasing the intake vacuum at the throat
    enough, to be pulling fuel from the high speed jet.

    http://www.marineenginedigest.com/diy/carb.htm