Honda gx630 oil sensor

Long time lurker here, but first post, you guys have saved my butt several times, thanks. I have a 5.5gpm with a honda gx630, everything worked last week fine, today I pull up to my first job and go to fire it up, it will start for 1 sec then oil light turns on and it shuts down. Checked the oil and it is fine. I tried to disconnect the wire, nothing, then tried to ground the wire, nothing, next hooked sensor wire to 12v and it will start but only run on 1 cylinder. Any advice before ordering a new oil sensor? Anybody know of a test or a bypass so I can finish out the week, thanks

I always thought unplugging the sensor would bypass it and allow the engine to run?


That was my understanding too, not too sure on this one.


Been looking cant find anything on this style of oil sensor, just the plug styles and the 2 wire sensors, this is the float style.

My 690 did that and I unplugged the sensor… so far so good, having my mechanic come in soon to do maintenance on all machines so I’ll see what he says

Replaced the oil sensor, still does not run, will start for 1 sec, red light comes on and it loses spark, any suggestions?

Unplug it, make sure it has oil in it?

Yeah unplugging it does not make a difference, oil is full, even changed the oil and filter when I swapped the oil sensor. I even tried too add a little extra oil to be safe, then drained the excess back to the correct level after that didnt work. Starting to think the issue may lie in either the harness or ignition, something must be grounding out the coil after it is started

Sounds like a job for a voltmeter. I’ve never seen the red light but it without a doubt has to be offering a clue. Good luck & let us know what you come up with.

Yeah gonna get out there tommorrow and start testing, its the red light that has me confused, I thought the oil sensor was the only thing that will turn the light on, if I cant figure it out tommorrow it will just go to the mechanic on monday, thanks for the suggestions

I don’t suppose you checked the fuse behind the ignition switch and all the connections including the rectifier underneath?

Yes fuse is good, tommorrow I am going to start checking wiring, connections, and if needed I have a gx690 that needs the pump rebuilt that I can borrow parts from.

Shoot man just take the 690 and slap an 8gpm pump on it.

You’re welcome.

The 690 already has a 8 gpm pump, its my main machine, the pump went out last week, cant get it in to get repacked until the 10th, the 630 with the 5.5gpm is my backup, was using it until the 8gpm is back up, now this happened. Just trying to get it by until I can get my trailer to the shop.

Got it fixed, removed the coils, wirebrushed the flywheel and contacts on the coils and gapped them, runs perfect now. Still dont know why it was triggering the low oil light though. Strange


It’s probably the only warning light the machine has, it was crying for help.