[HoosierDaddy]

FOLLOW-UP:
We completed the trip by manually holding the fuel stop solenoid open to start the generator. A minor inconvenience. I stopped by Bestgenman's shop on my way home and picked up a new fuel stop solenoid "just in case". After returning home in the comfort of my shop I found that the relay located on the generator was not getting proper voltage from the Martin Generator Control Box located at the back of the engine on top or the generator head. I believe I had checked that with a test light while troubleshooting "on the road" but when I checked with my volt meter it was only giving 9 volt. I had another box in a storage bay so I replaced it and that fixed it. The box is full of relays and other electronics and can be rebuilt.
Since the original fuel stop solenoid appeared to be old I decided to install the new one and store the old one in my spare parts box that my kids will sell at my estate sale. B-)
Thank you, Gordon for your patience in helping me by phone to trouble shoot this problem.

[DAN CASTOR]

This is my first time to ask a question....
My generator has had an on again off again issue now for about five years, somedays it works great for a few hours and somedays it won't run for over a few minutes....

I have read and studied what you all have said, 
And have replaced the following,

fuel pump
fuel filters several times
both oil sensors
both water sensors
That high dollar fire extinguisher
Thermostat
replaced the ceramic fuse in the front of the control box
Even went so far as added an electric fuel pump and filter assy like used on Reefer Trailer Units.

It will start then die

Just checked the power to the fuel soloined  with a test light, as long as I hold the fuel solenoid in it will run and the light will stay on, as soon as I turn it loose the light goes off,  it comes out and the unit dies.

Any one had this kind of fun with one of these?

Oh yeah, it is a 
Yanmar 4cyl 
 4TN82 ERK 
SER#04952
Unit is 263 a 1991 model

[HoosierDaddy]

Well, Dan it sounds like the only thing left is the control box that I ended up changing. Gordon is the generator guru...Hopefully he will chime in when he sees your post.

[Richard]

Could you elaborate on what you mean when you say hold the solenoid in? Are you physically holding it? Or are you holding it by holding the starter switch? Or something else?

---

Are there three wires or two wires on the fuel solenoid?

[ccjohnson]

We had similar issues. One time we took it Lofton Equipment in Phoenix. They are the Kohler dealer there. The tech worked on it all day. New brushes & slip ring for generator head. Still wouldn't make power so they switched out control boards. No luck. Finally they were able to trace it to a spade connector in the control box that was broken. It had been wrapped in black vinyl tape so it was a real hard thing to find. Next time the issue was an in-line diode to the fuel solenoid that I thought was just aa connector. Nice $5.00 parts fix. But, had to round trip to Phoenix to get it into the shop.

[Richard]

I learned by experience that adjusting the linkage between the solenoid and the fuel arm is backwards to me intuitively. My solenoid was not consistently pulling in so I shortened the linkage further pulling on the fuel arm. WRONG. That just made it worse. Gordon explained it to me. The plunger has to pull all the way into the coil to stay in the run position. So lengthening the linkage allowed the solenoid to fully "pull in"

[bestgenman]

First, tell me which generator manufacturer we are dealing with.  That will help.  

If the engine will stay running with the "stop solenoid" manually tied or held with the plunger full embedded and will not stay running if you release it , then your trouble is electrical.  Something in a series of switches is not making contact or a wiring issue (like the terminal story above).  This is where the brand is important as wiring schemes differ between makers.

Tell me if there are two or three wires on your stop solenoid.   As posted prior, the black (NEG) and red (IGN) are the hold in functions.  If you put a light or meter on these leads, does the light stay on while you hold the plunger in?

[bestgenman]

Dan, sorry ,l I missed your last sentence about the test light.  I think you might have a Kohler set but want your input.  The power to the solenoid will stop  (or light go out) if the engine slows down.  Try this,  from a good source of 12VDC, try powering the solenoid directly with the engine wiring disconnected to the red wire of the solenoid.  The air box heater relay mounted along the frame rail usually will have plenty of power, use your test light to find the wire with +12VDC, it will be on a 5/16" stud.  Use this to feed the red wire (it's best to have a 5 or 10 amp fuse in this wire), the black is already connected to neg. and push the plunger in , if it stays in your solenoid is working,  leave it connected for (you said 6 minutes and it quits) for 10 or 20 minutes.  The engine is not running in this test, we are testing the solenoid. Let me know how this works.

[DAN CASTOR]

It is a Kohler generator.
I was manually holding it in, and the light stays on, as soon as I release it the light goes off and it dies.
There are three wires all connected to one lug and one wire to the other,everything is painted beige,looks like a spray job to me, had to be at the VA all day today, will get back on it in the morning. Plan on scraping the paint and seeing what I have.
I did remove the solenoid late yesterday and hooked it direct to a battery charger set at low, it went in and stayed, but I only left it hooked for a few seconds, your thinking hook and leave for 10-20 minutes? I have not tried the above advise of adjusting the linkage yet.

[bestgenman]

Dan, how many wires come out of the solenoid?  Forget how many are connected.  You should not worry about linkage at this juncture, we'll get to that later.  Additionally, use battery power rather than charger power since it is not true DC and introduces more problems.

A picture would be helpful.