2146 confusing flooding issue

[corvettteguy]

My 2146 Onan powered 14 hp horizontal shaft drive has me
scratching my head. Starting cold is no issue, choke out, hit
the key and starts right up. Choke in and running smooths
out. Engage deck, full throttle, and start cutting grass.

All goes well 10min, 20 min or more then suddenly motor cuts
out and won't restart, smells like flooding. Wait until all
cools down and it will run again.

I know the Onan choke control STAR KNOB does not have a lot
of rotation and the choke pull only moves 3/8 inch. But I have
adjusted the knob so I get full open choke when pull knob is pushed in.
I first suspected the pull choke may be vibrating out a little, but now
I am not sure. Spark plug RL95YC threads are blackened.

What is my next troubleshooting step?
Any suggestions?

Thanks

 

[bertsmobile1]

Get an inline spar tester and fit it to the engine.
When it stops, check the tester to see if you have a spark.
If the magneto starts to break down you miss and get black smoke similar to flooding.

 

[corvettteguy]

Get an inline spar tester and fit it to the engine.
When it stops, check the tester to see if you have a spark.
If the magneto starts to break down you miss and get black smoke similar to flooding.

I do have the inline spark tester and I will give it a shot today.

Also, I will check to see when it is running well and warmed up I
will shut it down and try to restart.

 

[Rivets]

Check the fuel cap vent. If you are getting spark, the next time it happens as quickly as possibly open the cap and see if it will keep running. If you aren’t that fast, take the cap off, wait 10 seconds, put the cap back on and see if it will start. If it does replace the cap.

 

[corvettteguy]

I checked the spark yesterday and found that the
machine conked out after running only a few 100 feet,.
On the restart I saw the light flashing as It was
turning over.
Still a smell of gas.
So now the fuel /filter/carburetor/choke moves to
the forefront of possibilities.

I was afraid of that as the Onan carb is in
the 100's of dollars. Where a Kohler
or B&S is $26. So today I will see what
the carb looks like.

 

[bertsmobile1]

That is because the Onan carb is a much better carb.
Kohler tend to use Khlein carbs and they too are expensive because they are good and will outlast the rest of the engine.
You can fit any carb you like to your engine it just depends upon how much stuffing around you feel like doing with short lengths of stiff wire to hook it up

 

[cpurvis]

My 2140 has a Nikki carburetor and you're right; there are no cheap replacements available.

If the engine is starving for fuel, pulling out the choke when it starts to falter will smooth it out, but only for a brief time.

But you say you're smelling gas. I don't think that would happen if you were running out of fuel. It may be that your ignition is the problem.