Onan oil change now not running

kx125str99 wrote:
Hey guys so I finally had some time this weekend to get to storage and tinker with the generator. Ended up adjusting the idle screw. Runs bitchen now. Thanks for all the help guys.

1. Idle screw problem would NOT allow it to run 10 minutes and then die
2. You NEVER have to mess with the Idle screw at all. It is preset to a specific RPM(3600) and changing it will allow the voltage to change
3. It ran OK before Oil change? I doubt you messed with the Idle screw on a simple oil change.
4. While you THINK you found the problem, you have not. You need to check the NO load 120 voltage now, before you burn up any appliances. Doug

Hey guys so I finally had some time this weekend to get to storage and tinker with the generator. Ended up adjusting the idle screw. Runs bitchen now. Thanks for all the help guys.

We have a 4KY in a utility trailer. If the oil level is at the minimum level, it will run for about 5 minutes until it gets enough oil thrown around to trip the low oil shutdown. Once it all drips back down, it will restart and run for another 5 minutes or so. Make sure you are at the max level on the dipstick (not over) rather than at the min.

Wouldn't the oil level switch keep the engine from running at all, rather than let it run for 5-10 minutes before killing it? What's the use of a low oil switch if it lets you run for several minutes with insufficient lubrication?

the earlier models of 4KY (MicroLite 4000) used a low oil level safety switch in oil sump. I have seen this problem happen after oil change.
when oil is drained, the float on switch drops, then sticks at low position and does not come back up when oil is refilled. Onan did away with this switch somewhere around 96-97....and sent out service bulletin advising that the wire to the switch be disconnected. If you post complete model and spec, i.e 4KYFA26100_?, can determine if this applies to your genset.

Another vote for oil level. If you have problems after an oil change the chances are high that the problem is directly related to something you did wrong during the oil change - take out a little oil and see if that resolves the issue (low cost potential fix).

Dying after several minutes would seem to be heat related to me. I've heard that the fuel pumps somewhat often get heat-sensitive when they're dying or dead. These are pretty standard low-pressure electric fuel pumps, not difficult to get from auto parts stores etc. It's located underneath the starter solenoid and control boards on the left side of the generator; some quality time with a Torx screwdriver will get it out.

I think I've heard of a case where the coil also became heat-sensitive and would cut out after several minutes here, but that's not quite so common. It's possible that other electrical parts could similarly have trouble. I would check or replace the fuel pump first.

First thing is re-check the oil level. also the fuel level. Filters (Fuel and air) but I doubt those. Fuel is possible though. Beyond that I can not help much. I'm good at stops when you release the button, but not otherwise.

When it dies pull the spark plug to see if it’s wet from gas maybe flooding. There’s a small washer inside the carb bowl in the bottom did you get it back in .

Check fuel pump