• If you like antique engines, vintage tractors or old iron, please register and join us. When registering, please provide your CITY and STATE as your location!

Kohler 20rz eating starters; (won’t stop cranking)

allthumbs

Registered
Hi group,
I’ve got a late 80’s 20rz with Dec3 controller and about 600 hours. Recently I found it wouldn’t crank. Replaced the burnt out starter with Ford part from
Napa auto and the solenoid for good measure. The unit fired back up and I figured all was good. Come to Find after running it for 20mins or so without incident I then shut down and restarted it. At that point the starter stuck. I was unable to shut down the unit from the dec3; I had to cut fuel and disconnect the battery. I found the solenoid activated and the ‘I’ terminal on the solenoid with 12vdc. There was no voltage on the ‘S’ terminal of the solenoid. For good measure I sent the control board to flight systems who diagnosed it as no problem found. So far I’ve been through 2 solenoids and 2 starters. Not sure where to go from here but welcome any suggestions. Thanks in advance. Peter
 

pegasuspinto

Registered
There are about a zillion kinds of those 'ford' starter solenoids, they all look about alike and all have the same terminals, but the internal wiring is different. Quite possible you got the wrong one. There is also a lot of Chinese crap out there in both solenoids and starters. The correct Kohler one is 291891. You can get them on the internet pretty cheap, under $30.

The I terminal will have voltage on it while running. If the S terminal has no voltage but you're still cranking, your either got the wrong solenoid OR your solenoid is stuck. S is the crank feed from the controls.
 

radiodoc

Subscriber
Last Subscription Date
02/04/2021
Never too old to learn something. I had thought the "I" terminal bypassed the ignition coil resistor when cranking to give a hotter spark to the plugs.
 

pegasuspinto

Registered
It does. But when running, the voltage backfeeds from the resistor back to the I terminal....on THOSE applications. I terminal can also be the other end of the solenoid coil, and grounds to crank, or maybe grounds through a safety switch. Sometimes the coil gets it's power from one of the battery studs and grounds through the S terminal to crank. Some solenoids have one, two, or three terminals.

When you can't look up the coil by make-model-year, your local auto parts store can get you in trouble real fast with those solenoids.
 

allthumbs

Registered
@Pegasuspinto thank you for the information and suggestioks. I’m going to order the correct solenoid and see if that helps. I will report back. Peter
 

allthumbs

Registered
Update for the group- replacing the Napa/Echlin solenoid with a Kohler OEM unit 100% cleared up the issue. I'm up and running again for a grand total of about $30. Thank you to everyone who offered advice.

-Allthumbs
 

Mark Dieckmann

Registered
It is good to hear that you have it running. I am curious what is different about the Kohler solenoid? Maybe the I terminal is really just the other end of the coil? Not grounded internally?
 

BrianHaze

Subscriber
Last Subscription Date
11/08/2020
Kohler decision makers, 292806, 336415, gm28725 and gm64497 all have the same issue after a few years you could run into. A problem i like to call "ghosting"
It is a common issue flight systems sees in the repairs they do. I've had, since 2010 sent at least 100 of them into those guys.
So ghosting is when you start seeing the flywheels being chewed up, or the generator will not shut down, or in auto it randomly starts by itself(which is where ghosting came from)
From what ive been told, the problem is some static sensitive components that break down over the years. Shoot, I've even seen one where I barely brushed up against the board and it fired off.
 

pegasuspinto

Registered
It is good to hear that you have it running. I am curious what is different about the Kohler solenoid? Maybe the I terminal is really just the other end of the coil? Not grounded internally?
There are probably dozens of solenoid configurations, manufactures changed the pins depending on what made the wiring best for them. The problem is, auto parts stores can't look up generator parts, so they just guess. Most people guess it's a Ford solenoid, which even Ford had more then one style. Guess wrong, and it worn't work.

I have seen a 3 pin solenoid that would probably be a universal replacement, but it would require knowing what you have and wiring as needed. More then most people can do.
 

Ozark Lee

Registered
I had the same issue with a 30REOZ.

I initially had trouble with it not starting so I replaced the solenoid with whatever was the cheapest Ford solenoid from the O'Reilly Auto Parts that was about a block away. It started fine and exercised normally for about a month and then it missed an exercise and would not start again. I VOM'd it to the starter and it was getting power to the starter but no crank. Kohler wanted nearly $800.00 for a starter and John Deere, surprisingly, was about about $50.00 cheaper. I did some leg work and found a rebuilt on eBay for a skid steer that uses the same engine for $150.00. I installed the new starter and things were good again and I gave it several cycles. On the 3rd or 4th cycle I caught it not releasing the starter after the engine started and I quickly shut it down manually.

The problem traced back to the solenoid that I replaced with the cheap auto parts store part was sticking so I went to Kohler and bought the OEM part and haven't had any trouble since (about 2 years). The auto parts store version looked the same, wired the same, and initially behaved the same but the $15.00 savings was expensive. I have no idea what is so different between them but the auto parts store versions are trouble.

...Lee
 
Top