# L120 / Intek 20 HP Fuel Solenoid



## L120_Atlanta (Aug 23, 2012)

Can someone explain how the solenoid works for the carburetor on these Intek 20 engines? What is it even used for?

If I read the diagrams correctly (what I can find so far) all the kill switches ground out the magnetos to shut the mower off in various situations. So when does the carb need to cut off the fuel flow?

I'm thinking my current problem (posted earlier tonight) may currently be that the solenoid is not switching on and the previous problem may be a dirty carb AND intermittent solenoid switching COMBINED.

Now I'm guessing my brand new carb has no gas running through it because the solenoid is stopping the gas from flowing...

What I find as far as testing looks like it was intended for a single wire setup. These engines have two wires at the solenoid. Which wire would need the 9 to 12 volts to test? Is the other side a ground?

The little plug that goes to the two pins LOOKS to be polarized, but the socket / jack it goes into will accept the wire either direction.

Any help will be most appreciated!


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## L120_Atlanta (Aug 23, 2012)

*Very Strange, but SOLVED*

I guess reading over my posts it makes sense now. It didn't at the time, but here's what happened:

As far as I can tell, engine surge was from a carb issue. Something along the way from cleaning out the tank, changing the filter, replacing the pump and changing the carb fixed the issue, and it would still crank and surge with the fuel pump change-- the last thing I did before the carb swap and the total failure to crank.

You see, there was a second issue as well... The seat switch was not the problem (see earlier post) at least not unless there was a third issue too, LOL!... The power wire to the solenoid was broken back near the "firewall" for lack of a better term (steering support?), right where the fuel line comes around only just up under the shroud. When I went to repair it, from the color and condition of the wire at the break, this may have started at the factory, or soon after. The wire at that spot had been exposed for many years to look like that, but it only just stopped running completely, so there must have been a slight connection for a long time.

Most likely, when the engine started running rough from the carb issue, the vibration made the poor connection worse. Then either on its own, or when I was moving the fuel line which touched it near the break, the wire finally came apart.

I can say for certain it was not the actual carb replacement that broke it, because with the routing, there is no way to get tension that far back on the wire from the carb side of the engine. They're pretty strong wires too and there was actually a double break, several inches apart. It looks more like a double-crimp where the wire folded back during assembly... sort of a "Z-fold", if that makes sense.

Pretty frustrating to have spent this many hours on the problem. I still don't know if the phase of the plug matters at the solenoid. All I know is it works the direction it is plugged now, and that the white (or light grey?) wire that goes to the solenoid should be +12v and the black goes to ground.

I wasted the better part of two days on this one, so on the off chance this ever happens to anyone else-- remember to check for the solenoid "click". I even knew to do that-- I was used to the sound even though I didn't then realize what it was before. I actually assumed it was a fuel pump, but that appears to be vacuum driven.

I'm still not clear on which conditions shut off the solenoid though. Is it used for safety cutoff ("kill switches") or is that handled through grounding out the ignition?

I read somewhere this prevents flooding a cylinder with gas, but I wasn't quite certain why that would happen and how this would "know" to shut off the fuel flow in such case. Seems like the engine would have to be off in that case and then there would be no vacuum to push fuel INTO the carb to begin with...

Better run for now. I have some grass to cut...


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