89 Kohler genset won’t start

[CptBacardi]

Hello, I have an 89 Carver 38 Santego with a 4 cylinder Kohler generator which has a magneto. It was running fine last season, when all of a sudden it just shut down, as though it ran out of gas while under normal light load. The starter turns over just as fast as normal, but the engine won’t even “cough” as though it’s not even trying to start up... just spins. The battery is new.

I disconnected the white kill wire to the magneto, but engine won’t start. I assume that means I’m dealing with an engine issue, not a control panel issue right? From there I have tried spraying starter fluid in the carb to see if it will “cough” - nothing, but should indicate for me to look at compression and spark. The spark plugs are new. I removed them and they are not wet and the cylinders are dry. I use my thumb to verify best I can that compression is ok when spinning. Feels ok to me anyways. Next I put an inline spark tester bulb between the plug wires and each spark plug. The bulb has a very faint and quite intermittent spark. It’s not repetitive and mechanically timed on a cadence like I would expect. It seems like a weak spark compared to how bright the bulb would be on a typical coil based engine. So, this is leading me to the dreaded magneto. I’m not real sure what to inspect, clean, how to set gaps, etc... on that thing. All advice welcome please! If y’all need the model number, I’m not sure where to find it. I looked and couldn’t readily find one.

[ColRon]

CptBacardi, what model Kohler genset do you have? I assume it’s the same as mine, since I also have an 89 Santego 3867, and that would be the 7.5R23 Or 7.5R27. There are two subsets on this genset Referring to the circuitry with one being relay and the other solid state. I do have a service manual with a troubleshooting guide that should help you. Pm me you email address and I will forward you a pdf copy. There are about 7-8 differing issues that can cause that problem, but relays and circuit boards can also cause the same problem you are describing.

[ColRon]

One other note, the name plate should be on the carburetor side between the fuel pump and the control box. If you have the relay circuitry the control panel on the genset will have one swatch and two fuses, the solid state circuitry will have three switches and three fuses on the control panel.

[CptBacardi]

Thank you! I sent you a PM with email. I don’t recall off hand if the control panel has 1 or 3 switches, but if you are referring to toggle switches I believe there are 3. I think that because one of them is a 3 position “remote, off, and spring loaded start” that allows me to either use the inside switch for start or bypass it and try to start in the engine bay. I think there are 2 other switches that look the same because I have to look and make sure I’m flipping the correct one. I could be wrong though.

I have to drive down to the marina and make the long walk out to the boat to perform troubleshooting, which I am prepared to do today. Could you suggest any tools or equipment I need to bring with me?

One more thing. I thought if I disconnected the white kill wire from the magneto then that would bypass the control panel stuff and it would just be a simple engine. Is that not the case?

Thanks for your help

[ColRon]

If you have three switches then you have the solid state version, which means the control box contains a circuit board.

While I’m not sure, I don’t think just disconnecting the white kill wire will bypass the control panel. The genset have a few conditions which will cause it to shut down, such as overtemp and no oil pressure which are all controlled through the control box.

When you read the troubleshooting chart it will refer you to which section of the manual on how to test, remove, replace that sections items. From the you should be able to tell what equipment you may need.

The only real difference between the relay and solid state version is all contained within the control box.

[ColRon]

If you have the solid state version, did you try using the reset switch and then try recranking? For example,If the unit shut down due to an overheating (unit has two temp sensors, one cylinder head temp and one water temp sensor) condition, once the problem is corrected, you must “reset” the system prior to cranking. The middle toggle switch would be your reset switch.

[CptBacardi]

Ok, I have reviewed the manual. I do believe that I have the 7.5R (remote not auto) with the solid state. Since the unit did shut down last season WHILE it was running, perhaps a condition did exist for it to require a reset. I had no idea there was a reset, as it does try to crank as normal.

If I am reading this correct the only thing I need to do to perform a reset is to move the main switch to OFF, then toggle the RESET, and then move the main switch back to REMOTE and try to start? What does that actually do?

Man, it sure will be nice if that’s all it is. I had just recently replaced the impeller and changed the oil before this no start condition began.

[tomschauer]

Make a quick check of your oil level. Most have a low oil cut off.
If that's not it, trace the safety circuit for faults or lock outs.

[ColRon]

I have the relay version which doesn’t have the reset switch, but I assume that the reset switch is probably spring loaded and that it resets a circuit that has something to do the with control board. If resetting the system works then you will need to determine what condition caused the shut down in the first place.

Typically when a sensor is triggered it causes the circuit to ground, so as a quick way to test a sensor, you can disconnect each sensor in turn to prevent it from grounding. however, this is only a way to test the sensor and not a solution to the issue. Either determine the cause that activated the sensor or in the case of a sensor gone bad, replace it.

[ColRon]

In addition to checking your oil level, do you have the direct cooling system (raw water)or a heat exchanger (closed) cooling system? If closed, also check the level of your coolant.