Kohler 6EOD genset over crank error

[CaptainMarkS]

Am hoping to recruit some brainpower and experience in addressing a vexing issue with my 2010 Kohler 6EOD 6kw 60 Hz genset. When I try to start her, the engine turns but does not start. After 3 failed attempts, I get "OC" - over crank error on the electrical panel. I checked and bled fuel lines on the low pressure side - all fine. The engine turns manually both ways. The exhaust doesn't show signs of water intrusion.

Last week she was running fine. Yesterday we were in heavy seas, but nothing too dramatic. I would expect hydro lock / inability to turn engine if there were water intrusion.

Any ideas of how to start her up? We really need her to recharge batteries and refill water tanks after our passage!

[skipperpete]

The OC lockout is good protection against filling the exhaust with seawater, next attempt turn off the seawater intake until it fires up. If you’re certain that the fuel supply up to the injector pump is NOT the problem and the Glowplugs are all working, read on. I’m pretty sure your Kohler has the same engine as the small Northern lights 673 (and up) so probably the same stop solenoid but the Kohler wiring is different with the electronic control panel.
First check the senders for corrosion and function, there could be a fault in the shutdown circuit that’s cancelling the startup, then check the screw in “run” solenoid on the back of the injector pump housing and partially hidden by the fuel lift pump. The solenoid is “active to run” and allows the rack to move to no fuel when it’s disconnected .
However , if the solenoid is the same as the rest of the Kohler range (Woodward brand with 2 mounting screws) there is a potential risk of the “pull in” coil burning out due to too many start attempts and the engine won’t start until the solenoid is replaced.
Good genset but the electronic panel and Woodward solenoid are the downside.

[CaptainMarkS]

Thanks so much for that reply. I checked the high pressure lines and, indeed, there is no fuel coming out when the engine turns. I further tested the theory by applying voltage to the solenoid directly, using the starter battery. It didn't actuate at all.

This suggests your theory about the solenoid is spot on.

In order to conclusively test that theory, what would happen if I removed the solenoid entirely and then tried running the engine? I can be ready with a pin / nail the same gauge as the solenoid pin and insert it manually if I need to quickly turn off the engine should she run super rough or for some other reason.

Is this an okay strategy in your opinion? Thanks again for pointing me in the right direction!! This certainly beats having an engine with water intrusion damage. Speaking of which, I only get compression resistance when I turn the engine about 2/3rds a revolution. As a three cylinder, I'd have thought I'd get compression resistance with 1/3rd revolution? I should have paid closer attention when I did this in the past. Regardless, I sure hope that's not a sign I've got 2 of 3 pistons/rods bent from the cycling!!!

[CaptainMarkS]

Post mortem: it was indeed the fuel/stop solenoid. Engine started right up after removing it. Was able to depress the lever to stop the engine. Other than a bit of fuel sputtering out of the fixture, no harm done! I'm very pleased to have diagnosed the issue. Replacing the $250 part is easy enough.

[skipperpete]

Well before doing anything else you need to establish if the ground circuit is intact. Yes you can operate this genset by removing the run solenoid but you risk damaging the engine should a fault occur, particularly a low lube oil pressure shutdown, that little Perkins/ Shibaura/ caterpillar engine is notorious for oil pressure problems and if your engine is trying to protect itself (as with the OC) and you negate the shutdown circuit it will most likely damage itself. Does your engine panel have an oil pressure readout? If not, maybe remove the oil pressure sender (switch) and cold crank the engine using the manual stop until you get oil from the sender hole. If you don’t get oil with dead cranking, the regulating valve might be stuck but do the easy stuff first.
This all assumes that you do in fact have the PERKINS engine and not the wretched Lombardini or the air/liquid cooled Yanmar.

[skipperpete]

Oops, just saw your post, well done getting it running again. [emoji106]