New style GX390 no spark

Streetbu

So I'm working on a real Honda GX390. It doesnt have any spark, or should I say intermittent spark. When it does start, it runs fine for a little while, usually less than a minute, then just suddenly dies. Check spark, none. Oil level sensor is disconnected, replaced the coil with a genuine Honda part. Still no spark at times. Coil is gapped at .010 It has the newer style setup with three or four wires in the plastic connector that clicks into the coil. I'm lost. Who has any idea's?

BGW

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TJL

I have one at work doing the same thing. I hate these new coils.

Streetbu

I'm at work too.... There is no reason it shouldnt be. The body is grounded, it has switched power and ground going to it. Ive tried it with and without the low oil sensor hooked up. On top of that, it's a new Honda coil. But it's also the same issue it was having with the old coil... Im about to give up and swap the coil and flywheel with the old styel I have laying around. Only issue is the used flywheel isnt for electric start :(

Streetbu

Here's the wiring diagram

BLACK DEATH

How do you know if you have the old or new style gx390?

Streetbu

The ground wire on the old style coils is just that. A single wire that when you ground it, you kill the spark. The newer style coils have a plastic connector with 4 pins in it and three wires. It's requires a switched ground, switched 12v power, and the low oil sensor in order I function. It still uses the coil to generate the spark, but when the piston is at TDC, the magnet is several inches past the coil. Whereas on the old style coil the magnet will be right under the coil with the piston at TDC.

TJL

Thanks for the schematic, i'll use that. My prob motor is a gx270 but still, no reason for it to not have spark, it just doesn't.

sho305

According to that it only connects the black and red together from the coil to make it run, the battery power only goes to the starter to turn it over.

I read these advance the timing at higher rpm. They do that by retarding it at low rpm and doing nothing at high rpm, with the flywheel magnet advanced to make that happen. That is why the flywheels are different. So at low rpm the magnet would be past the coil but at high rpm it should not be, or only as much as the electronics slow down its response.

The way I see it you could only have a bad coil (not true if you just replaced it right?), or a bad switch, or a wire fault.

Streetbu

You were right Sho! Checked the old coil for the heck of it, it was bad, new coil does work. Chased a safety switch that was sticking at times and causing the no spark.

sho305

Good deal, now you have some extra cart riding time lol. Its kind of snowy to ride very often here, but I was on it for a few minutes this weekend. Didn't have any goggles on so I had to stop the snow was killing my eyes.