LT1042 Not Getting Gas

   / LT1042 Not Getting Gas #1  

sourwood

Member
Joined
Jan 25, 2009
Messages
26
Location
North Carolina
Tractor
Farmtrac 665DTC, Zetor 7711, Long 460, Long 310, Satoh S370D, Iseki 4100F, Case 380CK, John Deere 420C
Ok, I have an LT1042. Kohler Courage SV390.

Ran fine and then one day it would just turn over and never fire off. I checked the crank keyway and it was not sheered off. Checked and I have spark.

Thought about it- I had had this happen before and it was the fuel solenoid.

I checked the fuel solenoid, and sure enough the ethanol gas had gelled and rusted it and the plunger would not retract properly.

I rebuilt the carb and tried to order a fuel cutoff solenoid. I was told by the Ebay seller(and small engine dealer) that the fuel solenoid I needed was discontinued, but there was a replacement part and the replacement part had two wires instead of one wire. I was told to wire the one red wire on the new solenoid where the old solenoid had been and snip off the black wire.

I did that.

Now...

If I use ether- and I hate starting fluid with an intense passion- or even carb cleaner it will fire off.

However, the fuel filter is visible and the fuel filter is staying empty.

I've checked for obstructions all down the line. Nothing is pinched or obstructing it the fuel flow to the pump.

I've know that it could be either the little vacuum powered fuel pump or it could be the solenoid.

On the older Briggs engines with solenoids, you could just cut off the head of the solenoid, and put on a fuel shutoff valve.

Can I cut off the plunger on this solenoid on this Kohlers, and it work, and use a fuel shutoff valve ?

How I can I confirm whether the fuel "pump" is bad ?

Why would this thing not be sucking fuel other than the solenoid or the pump ? I rebuilt the carb correctly, I know.

Re: Cutting the black wire on the new solenoid: Was that bad advice on just cutting off that black wire coming off the fuel cutoff solenoid ? A snippet of the black wire still exists, I could take and ground it somewhere, if I solder on an extension. Should I use that ground it ?
 
   / LT1042 Not Getting Gas #2  
A solenoid needs a ground on one end of the coil and +12 volts on the other to operate. If the original had only one wire, the solenoid coil was probably grounded internally to the mounting bracket. I would guess that the black wire should be grounded to the tractor frame via a mounting bolt etc.

Bob B.
 
   / LT1042 Not Getting Gas #3  
You cam test that solenoid with some gator clip jumpers. Black to ground red to +. If you hear a click you know it's working. Reattach the black to ground. Test first.
 
   / LT1042 Not Getting Gas #4  
You can test the little pulse fuel pump if you remove it and use your mouth to generate little plus/minus pressure pulses on the pulse line (the one that normally connects to the crankcase somewhere). Slight pressure is all that's needed. It is thin rubber diaphragm pump. Use a couple of short sections of clean/new vacuum or fuel hose. Submerge the suction line in something liquid. Water will work as long as you dry it all out before re-installing. The volume pumped is quite small per pulse, so don't give up too easy. It will take a while to "prime" the air out of the pump while you are testing. Remember that at 2000-3000 engine RPM, there's 2000-3000 pulses/minute!

I agree that you will probably need to connect the black solenoid wire to a ground for it to work. But testing the solenoid with a 12v source is the definitive test. No click means no work.

- Jay
 
 
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