Onan generator choke help

[emcee]

The generator has always had these issues:


1. Cranks at least 30 seconds (longer in winter) before starting.
2. Putters (dieseling?) about 5 seconds after shut down.
3. Cranks and sputters for at least 30 seconds when attempting to start soon after a shut down.


I have noticed that before a cold start when I gently pull the choke rod (see photo) to the left, there is at first a slight resistance then the rod is free and the spring pulls it the rest of the way to the left. It will then start in 10 seconds or less.


What can I do?

[OLYLEN]

Sounds like a fuel problem, that may not be choke. HAVE you changed the fuel filter, and checked fuel pump for flow?

LEN

[avfordguy]

Originally Posted by emcee

The generator has always had these issues:


1. Cranks at least 30 seconds (longer in winter) before starting.
2. Putters (dieseling?) about 5 seconds after shut down.
3. Cranks and sputters for at least 30 seconds when attempting to start soon after a shut down.


I have noticed that before a cold start when I gently pull the choke rod (see photo) to the left, there is at first a slight resistance then the rod is free and the spring pulls it the rest of the way to the left. It will then start in 10 seconds or less.


What can I do?

That silver disc to the far right in your picture is the bimetalic choke spring, whencoldloosen the nut and turn it so that the rod holds the choke on the carb tighter, they come from onan set for hot climates.

[Waiter21]

Adjust the choke.

See that little round disk shaped thing in the upper right corner.. Loosen the nut on the upper right side of it so you can turn it. Then rotate that round disk thing about 45 - 90 degrees CCW.


I did a short article with photos when I adjusted mine:

Onan Generator Choke Adjustment – 2001 Coachmen Mirada 300QB


..

[emcee]

Originally Posted by Waiter21

Adjust the choke.

See that little round disk shaped thing in the upper right corner.. Loosen the nut on the upper right side of it so you can turn it. Then rotate that round disk thing about 45 - 90 degrees CCW.


I did a short article with photos when I adjusted mine:

Onan Generator Choke Adjustment – 2001 Coachmen Mirada 300QB


..

That worked perfectly!


It was only recently that I realized the generator was not starting correctly. That's because the generator in my previous MH was the same way and I never knew it could be better. So I have been living with this for about 6 years!


Thanks!

[exrench]

Just be happy that your starter motor survived!

[Waiter21]

That worked perfectly!

GREAT. As AvFordGuy said, I believe Onan originally adjusts these for summer use in Death Valley.. :-)

[BirchyBoy]

Great thread! I need to save this and make this adjustment on mine. It always takes 20-30 seconds to start.

[1972VWbus]

The correct method for adjustment is as follows:

1. Allow the gen set to cool down. In side the housing needs to be the same as ambient temp.

2. Loosen the adjustment screw holding the adjustment plate.

3. Slowly rotate the adjustment plate until the bi-metal choke shaft connection is visible in the sight window. This is the correct setting for ambient temperature of 70 F (21 C) If the ambient temperature is higher or lower than 70 F (21 C), make a mark on the choke coil housing opposite the center mark on the adjustment plate. Each mark on the adjustment plate is equal to 10 F (12.2 C) of difference from 70 F (21 C). If it is warmer than 70 F (21C), rotate the plate clockwise. If the temperature is less than 70 F (21 C), rotate the plate counterclockwise. Tighten the adjustment screw.

Example: If the ambient temperature is 90 F(32 C), rotate the adjustment plate two marks clockwise from the 70 F (21 C) position marked on the housing.

4.Move the choke lever back and forth to check for free movement. Verify that the choke does not bind or stick.

[1972VWbus]

One can use either the video camera on their phone or a snake camera that connects to your phone to view into the sight window on the generator choke housing.

Such as the following: https://www.amazon.com/s?k=snake+cam...f=nb_sb_noss_1

[THenne1713]

Google online and download the KY 4000 SERVICE MANUAL, FREE, EASY TO FIND, and should give step by step details on adjusting choke properly. BUT part of your description implies maybe just a choke rod bent wrong, rubbing/ hitting something? Check that FIRST. If linkage NOT the issue, often old fuel Evaporated, leaving a VARNISH and this varnish becomes GLUE, and some CARB/CHOKE CLEANER aerosol spray might cure all issues.
WEAR SAFETY GLASSES/ GOGGLES,
GOOD LUCK.

[89sandman]

Mine was the same when I got it, crank, crank, crank before it would start. So I was going out and holding the choke closed by hand and using the button on the gen to start it. Not a big deal since we use a 2000 watt inverter gen. 99% of the time. Finally got the time to do a google search to see how to adjust it. I have the notch set in the 9 oclock position now and it starts as it should.

[1972VWbus]

The following is from the manual....

1. Allow the gen set to cool down. In side the housing needs to be the same as ambient temp.

2. Loosen the adjustment screw holding the adjustment plate.

3. Slowly rotate the adjustment plate until the bi-metal choke shaft connection is visible in the sight window. This is the correct setting for ambient temperature of 70 F (21 C) If the ambient temperature is higher or lower than 70 F (21 C), make a mark on the choke coil housing opposite the center mark on the adjustment plate. Each mark on the adjustment plate is equal to 10 F (12.2 C) of difference from 70 F (21 C). If it is warmer than 70 F (21C), rotate the plate clockwise. If the temperature is less than 70 F (21 C), rotate the plate counterclockwise. Tighten the adjustment screw.

Example: If the ambient temperature is 90 F(32 C), rotate the adjustment plate two marks clockwise from the 70 F (21 C) position marked on the housing.

4.Move the choke lever back and forth to check for free movement. Verify that the choke does not bind or stick.

[THenne1713]

I suggest (Annually?) First spray choke and shaft with carb cleaner to remove any varnish that maybe impeding proper operation.