EDIT: Never mind my request for you to report the orientation of the part described below. I now believe it does not matter. I will continue to update the thread re my troubleshooting findings.FINAL EDIT: Solved. It was adjusted too lean from the factory. In this condition, the coil will hang/stick until you pull on the rod by hand. Once I adjusted the setting per the manual, it works fine.ORIGINAL POST:If you have modern Onan 4KY gas genset, can you look at the choke adjustment disk as shown in the photo below, and report if the adjustment lines are on the left side of the circle, or on the right side like mine in the photo? I'm having a problem with something inside that housing hanging up. And it's not the rod hanging up on the hole. It's something inside. Both the service and parts manuals show the notches on the left side. So I would like to hear where your lines are. Maybe my disk is installed 180 degrees off, and maybe that is causing the sticking. When you read the adjustment procedure, it makes NO sense that the holding nut would be covering several of the lines. Thanks!

That housing contains the thermal spring for setting the choke based on the temperature.In my case, this thermal spring goes to a full hot position when the gen warms up to operating temperature AND THEN HANGS UP there. So during the next cold start cycle the choke is stuck in the full open (non choke) position and the gen set will not fire up.I have fiddled with this for years to no avail. So, I have just gotten used to manually dislodging the stuck spring when cold so I have some choke applied before I try to crank it over.I too will be very interested if someone knows the secret to this problem.

That is exactly what is happening with mine. I intend to get to the bottom of it.The way my previous Onan acted, it may have had the same problem.Looking at the tab or tabs on the center of the disk, there could be some directionality problem if it is installed 180 degrees off. So Harvard, which side are the adjustment lines on on yours?

I believe the metal coil element is going overcenter as it lengthens.Here is the inside of the adjuster, from an ebay listing. The orientation of the prongs is not going to affect anything.Here is a picture of the element. I rotated it and added a line to mimic the rod going to the choke lever. The coil expands as it warms up. It lengthens, and the end of it moves to the left in the photo, pulling the choke rod. So that end is either continuing to wrap around the circle and then getting stuck as it cools, or the tab sticking up is catching something. Or the little cover no. 11 shown in the parts drawing is catching something.I'm going to get my MH into my workshop later this week. The choke is stuck open now. I will get something figured out.

Sorry, my unit is at a remote storage facility so it will be awhile for me to make/capture any observations.

The way I adjusted my thermal spring was to set the choke just closed at a normal summer day (about 60F) with the spring at OAT. The choke still locked up choke open when full hot after it cooled down.

SOLVED: look at your Onan 4K genset for me? | Good Sam Community

mchero
Explorer
Nov 08, 2016
EXCELLENT point Snowman.
Snowman9000
Explorer
Nov 08, 2016
Harvard wrote:
How about a picture of your final setting? TIA.

I don't think it matters because every coil is unique. If you looked at 20 different ones all set correctly, there would probably be 20 different positions. If that was not the case, they would not have the type of adjustment mechanism that they do.
Harvard
Explorer
Nov 08, 2016
How about a picture of your final setting? TIA.
Snowman9000
Explorer
Nov 08, 2016
Well, it's working. It was 2 marks too lean from the factory. In that condition, it binds and you have to pull on the rod to free it up. When it is set correctly, it does not bind. To be more exact, it binds lightly but pops free when the engine starts to crank. I have run it a few cycles now to be sure.

I did not guess it could be that simple.

Service manuals. Choose 981-530C.
Adjustment shown on page 8-12.
Snowman9000
Explorer
Nov 08, 2016
j-d, as you know, it's very tight inside the genset housing. I did see that in my installation, I can remove the 4 bolts that hold the housing, and lift the housing inside the compartment, about 3 inches. That would give me enough room to work. But still, it's not something I am going to do if I don't have to.

And yeah, my previous MH's Onan 4KY acted the exact same way. But I never adjusted the choke on it. Always meant to. But you know how that goes.
j-d
Explorer II
Nov 08, 2016
What with the issues several of us are having... I hadn't seen anybody mention this condition till this thread... I was actually reluctant to even look at the thing! Leave it alone and it'll leave me alone...

But... OP: Have you dismantled this little trouble spot? If you haven't, I'm gonna say I don't recommend that you do, since it seems to touchy.

But... If you have, and successfully re-assembled it... How about taking that bi-metal coil out again? Lay it on a cookie sheet, and heat it with a hair drier. Maybe you happen to have a coil that expands in an unintended way, and puts itself in a bind...
bucky
Explorer II
Nov 08, 2016
$300
mchero
Explorer
Nov 07, 2016
Has anybody discussed the issue with an Onan tech? Wonder what they would tell ya?
Snowman9000
Explorer
Nov 07, 2016
lane hog wrote:
Huh. I've always wondered what that was...

The aluminum duct on the bottom has been disconnected on my 4K since, well, forever. Hadn't noticed any unusual behavior before, but maybe it's worth a few wraps of foil tape on to hold it all together...

It needs to get hot pretty quickly, so that the choke is opened quickly. So yeah, I think it would run better if you fix that.
lane_hog
Explorer II
Nov 07, 2016
Huh. I've always wondered what that was...

The aluminum duct on the bottom has been disconnected on my 4K since, well, forever. Hadn't noticed any unusual behavior before, but maybe it's worth a few wraps of foil tape on to hold it all together...

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SOLVED: look at your Onan 4K genset for me?

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