carb solenoid

[Norm Wampler]

Morning,
I really appreciate all your comments on my old tractor. This is a pretty neat page to get advice from and try to do things yourself. I had posted some questions about the carb solenoid on my Massey Ferguson 135 Perkins gas 3 cylinder. I finally found a new solenoid and bought it last night. Can any of you explain just how it works? It seems to have a spring inside and a little protruding pin. Does this pin push on the float? I had the carb apart when a put a kit in it and I don't remember seeing anything else.
Any help or advice would be appreciated.
Thanks,
Norm

 

[Ray IN]

My 3020 has one in the carb and works well to prevent run-on. It shuts off the fuel supply when the power is killed. The spring closes the needle into a seat which blocks the flow of fuel from the bowl up the jet. At least that is how I understand it. What I am not so sure about is adjusting the carb through it. Mine has an adjustment that you screw in or out to change the high speed fuel mixture, but I can not really see any difference when I have tried to adjust it.

 

[Steve@Advance]

The solenoid valve closes the main jet fuel supply when the ignition switch is turned off, thus stopping the fuel entering the intake while the engine is coasting to a stop.

That's all it does.

There is still fuel in the bowl, here is still fuel being delivered to the float valve.

So, don't be confused about what it does.

It does not replace the need to close the fuel valve on a gravity fed fuel system when not in use.

It does not empty the bowl for long term storage, there is still fuel in the bowl.

 

[Geo-TH,In]

Steve.
Terramite put an in line solenoid to prevent gas from getting to the carb. The carb solenoid on 20 hp Honda shuts off high and low speed fuel, while the carb solenoid on 20 hp kohler only shuts off fuel to low speed jet. Don't ask me why, but that's who it works, because I use carb solenoid to stop engines so I don't get any backfire in muffler or dieseling.

After my jubilee and Farmall C leaks gas when not in use, I also installed inline solenoids of both of them.
geo.