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  1. #1
    Member
    Join Date
    Aug 2009
    Location
    Marsh harbour
    Posts
    1

    Yamaha 300 HPDI engine problems- HELP!!

    I have a Regulator in the Bahamas fitted with twin 2004 Yamaha 300 HPDI which has been running fine until now, 540 hours both engines.

    a problem has just developed with 1 engine.

    will not idle out of gear and stalls, belches smoke when first started, 20% down on engine revs and power for same throttle as other engine, and consuming 30% more gas than other engine at identical RPM.

    plugs changed with no effect.

    yamaha dealer and technician cannot identify any fault, even with Yamaha diagnostic tools!!

    anyone had a similar problem, and what was the cause??

  2.  
  3. Member
    Join Date
    Aug 2008
    Location
    Lorain
    Posts
    201
    #2

    Re: Yamaha 300 HPDI engine problems- HELP!! (Exodus)

    Unless already done I would start with a compression test. Was that done? I would think a tech would have done that but you did not mention if it was checked.

  4. Member
    Join Date
    Nov 2005
    Location
    Prairieville, Louisiana / Zolfo Springs, Florida
    Posts
    5,105
    #3

    Re: Yamaha 300 HPDI engine problems- HELP!! (Exodus)

    Also need to start checking filters and connect a pressure gauge to the top of the VST and see what kind of pressure you have at the medium pressure fuel pump,


    THE SHADOW One blink and she's gone! Will leave you wondering if you really saw her!


  5. Member
    Join Date
    Oct 2006
    Location
    Hollywood
    Posts
    64
    #4

    Re: Yamaha 300 HPDI engine problems- HELP!! (Exodus)

    There was an update on the "TPS Sensor" to raise the voltage from .55 to .58. My motors were stalling at start-up and then when this update was done (a month ago) the stalling stopped. I can't answer the question about your fuel consumption however....

  6. Member
    Join Date
    Sep 2004
    Location
    Launceston
    Posts
    225
    #5

    Re: Yamaha 300 HPDI engine problems- HELP!! (Special K III)

    Follow the sticky for your low pressure fuel pumps. They will cause excess fuel consumption, smoke and a blown engine... It is a quick check and I'd do it before using it again

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