John Deere 430

[Kyow]

Restored a 430, new carb, dist, points, coil - starts but will not run more than a few seconds.
Replaced electronic ignition someone had installed in the past. What is my problem?

 

[oldnslo]

Either fuel or spark would be two most obvious problems.

Easy enough to check for spark.

On fuel would have to check if fuel pump is operating and suppling has to carb.

 

[radios1]

if you look at the spark plug, and it's wet, it's probably losing ignition, if the plug is dry, it's probably not getting fuel..

 

[Roadworthy]

Assuming the engine is getting adequate air (no choke after start, etc.) my guess is lack of spark rather than fuel. It should run for a couple of minutes or more if you fill the float bowl in the carburetor. I'm basing that on the fact my pickup will run about a mile just on fuel in the float bowl but that's another story. One side of the coil goes to the ignition switch. Make sure it's still hot after the engine dies. If it is still hot you can narrow the problem to the coil, points, or condenser.

 

[radios1]

Assuming the engine is getting adequate air (no choke after start, etc.) my guess is lack of spark rather than fuel. It should run for a couple of minutes or more if you fill the float bowl in the carburetor. I'm basing that on the fact my pickup will run about a mile just on fuel in the float bowl but that's another story. One side of the coil goes to the ignition switch. Make sure it's still hot after the engine dies. If it is still hot you can narrow the problem to the coil, points, or condenser.

if it was spark, then the spark plug would be wet from fuel..

 

[rScotty]

Well, it sounds like fuel to me. Plus it's easy to check for spark - both primary as in voltage to the coil, and secondary by looking at the spark.

What do you do to get it to run for another few seconds?

So I'm guessing it's fuel.... if I forget to manually turn on the gas tap, my 530 will run about 10 seconds on the gas in the float bowl. Just about long enough for me to decide to undo the choke and then it slows down and down and stops running. No amount of cranking will help....it's out of fuel.

Now when I still had the factory automatic fuel tap hooked up, it became a lot harder to figure out what was going on when it wouldn't start. I'm wondering if yours has that automatic fuel shut off? It was characterized by a diaphram, spring, and an oil pressure line that went to the top of the fuel bowl. Those automatic fuel taps can sure cause problems.

When I went to my JD dealer to get parts for the automatic fuel shut off valve he said that they had so many problems with the fuel diaphrams lately that he was stocking a manual valve to replace the automatic fuel valve.... that was back in 2014 I think.

The other thing it could be fuel wise is that the needle and seat is not working properly - that's the number 1 issue with carburettors & always has been.
BTW, #2 is a plugged idle jet passage, but yours doesn't show those symptoms. #3 is a partly blocked main jet circuit - and yours doesn't show those either.

rScotty