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How adjust Onan 6.5 genset idle/running ?

Discussion in 'Chris Craft Connies, Commanders & Catalinas' started by Pancho, May 19, 2009.

  1. Pancho

    Pancho New Member

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    How adjust Onan 6.5 genset idle/running ?

    Genset seems to not be running at high enough RPM's. Seems to idle fast enough, but not certain. Issue is that it does not run fast enough when I turn the air conditioner on, because volt gauge on switch panel says 100 volts, and unit should get at least 110V. When I switch on air, I can hear the genset labor/react but it doesn't seem to run fast enough to put out the necessary juice.

    Some guy told me, "Your not supposed to adjust it. It was set at the factory". Yeah right, it was set at the factory 25 years ago.

    Any help, other than "It was set at the factory", would be much appreciated.

    Thanks

    PS.
    Genset: Onan 6.5 (McGraw Edison) Model #: 6.5 MCCK 3CR / H
    A/C: Marine Air, I think 11G btu.
  2. dennismc

    dennismc Senior Member

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    You will need a hertz meter to do that, I believe it is adjusted at the end of the governor lever, contact Onan for exact location of adjustment, adjust hertz to 60 cycle, plus or minus 3%
  3. BEARVT

    BEARVT New Member

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    1981 onan 6.5kw

    the generator only runs with starter motor then dies as if it is not getting spark when starter is released. any ideas. does anyone have a service manual to share?
    thanks
  4. dennismc

    dennismc Senior Member

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    contact Onan on line and check for online service manuals, you may have to search under Cummins/Onan.
  5. NYCAP123

    NYCAP123 Senior Member

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    Did you check water and fuel flow?
  6. Marmot

    Marmot Senior Member

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    When guessing and hoping the guy next to you at the bar might know ...

    RTFM
  7. Pascal

    Pascal Senior Member

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    voltage is not adjusted by RPM! RPM affects frequency, NOT voltage. You do not want to mess with RPM unless you have a reliable Freq. meter.

    Voltage is usually adjusted thru voltage regulator but you will need a manual for specifics.

    typically when a genny starts but dies when the run or start switch are released, the problem can often be traced to one of the safety switches or circuit. It's not too hard to troubleshoot when you have the wiring diagram.
  8. Marmot

    Marmot Senior Member

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    Oops, it should have read;

    "When guessing and hoping the guy next to you at the bar might know doesn't work ... RTFM
  9. Henning

    Henning Senior Member

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    If it is old enough to have points, most likely you have a bad ballast resistor. Otherwise very likely the switch.
  10. BEARVT

    BEARVT New Member

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    yes. is there a relay that engages with the starter and gives power to the points then cuts off the power to th epoints when the unit is shutdown?
  11. BEARVT

    BEARVT New Member

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    are you aware of a relay that engages with the starter then cuts off power to the points when the unit is shut down? it fires on both cylinders as long as i have the starter engaged a the exhaust manifold is hot on both cylinders.
  12. Marmot

    Marmot Senior Member

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    Try this, it's from TFM :D

    Attached Files:

  13. BEARVT

    BEARVT New Member

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    thanks
    would you have one or a servide manual available??
  14. BEARVT

    BEARVT New Member

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    thanks, i'll give it a try. do you know if there is one device that is typical to fail?
  15. Marmot

    Marmot Senior Member

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    "Exclude the bits that won't stop it from working and you will have your answer, Grasshopper." (from a Chen Dynasty troubleshooting manual written by Okaie Yoo RonSoon )
    Last edited: Oct 19, 2009
  16. BEARVT

    BEARVT New Member

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    Thanks Again. I'll Try The Process Of Elimination
  17. Henning

    Henning Senior Member

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    The starter solenoid often has an "S" terminal that is wired to the coil in parallel to the primary ignition circuit (which has the ballast resistor in line). This feeds full juice to the coil during the cold start up but goes away after the solenoid disengages to keep you from melting the points.
  18. Marmot

    Marmot Senior Member

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    And it is often wired as shown in the wiring schematic and works as detailed in the description provided in the manual. Geez, Henning, RTFM to which a link has been provided.

    No wonder people have problems getting stuff to work. :rolleyes:
  19. K1W1

    K1W1 Senior Member

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    Hi,

    The statement above is kind of alarmist to put it mildly. If the points were burnt out they thing would not start at all.

    Here is a brief explanation of what a Ballast Resistor actually does when used in a system.

    Ballast Resistor: This is an electrical resistor that is switched in and out of the supply voltage to the ignition coil. The ballast resistor lowers voltage after the engine is started to reduce wear on ignition components. It also makes the engine much easier to start by effectively doubling the voltage provided to the ignition coil when the engine is being cranked. Not all manufacturers used a ballast resistor in their ignition systems So you should check to see if yours does.
  20. BEARVT

    BEARVT New Member

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    thanks for the info on the ballast resistor. i may have a faulty ballast resistor. i'll check voltage on both sides tomorrow. will the generator run on the start circuit if it is bad? i checked the continuity on the exhaust hi temp and hi temp water shut offs and both have closed circuits. there are two bosch relays in the power panel. i believe one is for the generator and the other may be for the ignition circuit. i suspect that may be the issue. any thoughts on this theory? does anyone have a manual to share??