Onan 4K gen?

[udidwht]

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.

[udidwht]

OK adjusted these valves and found that the intake was .003 and the exhaust was a slightly snug .002. Both reset to .002 (Generator has 512 hours).

When you adjust the valves turn the fan by hand (engine cold) clockwise and watch each valve open then close. When both valves are closed then make your adjustment using a feeler gauge .002

One tip always slide the feeler gauge from straight beneath the rocker arm. Going in from either side of the rocker arm will tend to give you a false snug reading. Helps to to hold the push rod side of the rocker arm against the push-rod to take up any slack that may be between the rocker arm and push-rod.

On my Micro 4K the adjustment nut is self locking. There is no torx screw in the center of the adjustment nut. Turning the nut is stiff but once the lash is set its set. After adjusting always recheck the lash before moving to the next valve.

And be sure and have an extra gasket in the event it tears (mine did) when removing the cover. The cover nuts only need to be snug once screwed in finger tight.

One other note:

If you turn the fan counterclockwise the starter may not engage when you hit the start button. Repeated clicking may arise. Batteries I know are good and grounds were cleaned well 1 week ago. Moving it counter clockwise may disengage the actuator allowing for the no start issue.

Reach in with your hand and give the fan a few turns clockwise and then attempt
the start. I had to do this a few times. Once the generator started I ran it for 15 mins or so then shutdown. Then waited a few minutes and restarted from inside the coach. Generator started great from inside as well.

As for the feel of the lash adjustment start by tightening until it just grabs the feeler gauge then slightly back off until the feeler gauge moves freely with no binding or heavy drag.

The following is a picture of the valves with cover off. Both valves are closed in the pic. Note the absence of torx adjust screw in the center of the hold down nut.

https://www.dropbox.com/s/qkds0ugwcgtauie/20180605_185532%5B1%5D.jpg?dl=0

[Kpackpackkelley]

udidwht wrote:

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.

Should be pretty easy to get into smokestak I’m a member there

[road-runner]

KY spec A to G here http://www.twinslan.net/~n0nas/manuals/onan/981-0503%20Onan%20KY%20MicroLite%204000%20Series%20RV%20...

Other manuals here http://www.twinslan.net/~n0nas/manuals/onan/

[udidwht]

road-runner wrote:

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.

I adjust them on my 72 VW bus with both closed for each cylinder. Starting with cylinder 1. This only has one cylinder but the principal is the same adjust with valve/s closed.

Is there a service manual on line for this generator (4KYFA26100B)
120v/33.3 Amps/60hz/12v/3600rpm/kW:4/Ph:1/Pf:1AC volts: 120

[road-runner]

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.

[udidwht]

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.

[Kpackpackkelley]

Here’s your parts manual. Look for spec b parts. Your valves will be side by side . The one closest to the muffler is your exhaust valve. Sometimes you can save the gasket after taking the screws out if the cover is stuck tap on it a little bit.
https://www.dropbox.com/s/hzj5ospf1wajbn9/0981-0246_I35_201706kyparts.pdf?dl=0

[udidwht]

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.

[Kpackpackkelley]

That’s the way the onan techs that I know tell me how to set them on the ky

[udidwht]

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)?

[Kpackpackkelley]

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.

[maillemaker]

I highly recommend this forum for all serious technical questions regarding Onan generators:

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

Steve

[Kpackpackkelley]

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.

[CloudDriver]

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.