Forum Discussion

udidwht's avatar
udidwht
Explorer
May 02, 2018

Onan 4K gen?

Alright I've got an Onan MicroQuiet 4000 and I need to adjust the valves. The model # is 4KYFA26100B

Anyone know how it's turned over by hand to get the piston TDC prior to lash check. Will it turn via the fan by hand? How about any video of such procedure?

I do this on my 72 VW Type-4 motor every 3000 by turning the engine counterclockwise via the alternator fan pulley nut. Curious if the generator can be turned via the fan as well.

Much appreciated.
  • CloudDriver's avatar
    CloudDriver
    Explorer
    May 02, 2018
    Yes, the engine can be turned over by hand using the fan blades. You likely already know to pull the spark plug wire off the spark plug before doing so.

    When you are done, please post your experience with adjusting the valve lash as our Onan is over the 450 hour recommended service time to do this. I've been procrastinating doing this job.
  • Kpackpackkelley's avatar
    Kpackpackkelley
    Explorer II
    May 02, 2018
    Pull the spark plug so it’s easy to turn. Turn the fan clockwise. Check the valve setting to see where your at you may not need to set them and you’ll get experience.Then post here.
  • maillemaker's avatar
    maillemaker
    Explorer
    May 02, 2018
    I highly recommend this forum for all serious technical questions regarding Onan generators:

    https://www.smokstak.com/forum/forumdisplay.php?f=1

    Steve
  • Kpackpackkelley's avatar
    Kpackpackkelley
    Explorer II
    May 02, 2018
    Open intake all the way open and set exhaust valve .003 then rotate till exhaust is all the way open and set intake .003 on that model. But first check your setting before you move anything.
  • udidwht's avatar
    udidwht
    Explorer
    May 02, 2018
    Kpackpackkelley wrote:
    Open intake all the way open and set exhaust valve .003 then rotate till exhaust is all the way open and set intake .003 on that model. But first check your setting before you move anything.


    Any reason not to adjust them when both valves are closed?

    .003 is the lash for both valves (stone cold)?
  • udidwht's avatar
    udidwht
    Explorer
    May 03, 2018
    Kpackpackkelley wrote:
    That’s the way the onan techs that I know tell me how to set them on the ky


    Will do. I take it the intake is the top one? As for the gasket does it need replacing? If so you have the part number handy much appreciated. I also need to replace the fuel filter.

    I've looked at the Onan site and it is not easily navigable for parts on these.

    Thanks for the assistance.
  • udidwht's avatar
    udidwht
    Explorer
    May 20, 2018
    maillemaker wrote:
    I highly recommend this forum for all serious technical questions regarding Onan generators:

    https://www.smokstak.com/forum/forumdisplay.php?f=1

    Steve


    Registered but never received an email back (check spam folder and nothing). Do not know how to get a hold of the moderator to resolve it so I can sign in.
  • road-runner's avatar
    road-runner
    Explorer III
    May 21, 2018
    udidwht wrote:
    Kpackpackkelley wrote:
    Open intake all the way open and set exhaust valve .003 then rotate till exhaust is all the way open and set intake .003 on that model. But first check your setting before you move anything.


    Any reason not to adjust them when both valves are closed?

    .003 is the lash for both valves (stone cold)?
    I'd guess that when one valve is fully open you can be sure that the other is fully closed, so you don't have to worry about finding TDC. The service manual specs say the lash is 0.002, and the clearances sections gives the range as 0.0008 to 0.0032. It says to adjust both at TDC when they are both fully closed.

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