JD X350 cranks but wont start

My understanding is all X-series machines have an ECM (Interlock Module). On earlier machines it was a separate module located behind the instrument panel (i.e. hour meter/fuel gauge). On the newer machines with the large LCD display the Interlock Module may be integrated into the display panel.

Are you sure the carburetor fuel cutoff solenoid is working? You said you confirmed fuel is getting TO the carburetor but are you sure it is getting THROUGH the carburetor? The shutoff solenoid will prevent fuel getting to the main jet if it is not working. The Interlock Module controls spark and the fuel cutoff solenoid. If you have spark then the Interlock Module is probably not in a condition that is prohibiting the starting of the engine.

Did you try a shot of starting fluid? With spark and compression that will allow the engine to start and run for a few seconds.

jgayman said:

My understanding is all X-series machines have an ECM (Interlock Module). On earlier machines it was a separate module located behind the instrument panel (i.e. hour meter/fuel gauge). On the newer machines with the large LCD display the Interlock Module may be integrated into the display panel.

Are you sure the carburetor fuel cutoff solenoid is working? You said you confirmed fuel is getting TO the carburetor but are you sure it is getting THROUGH the carburetor? The shutoff solenoid will prevent fuel getting to the main jet if it is not working. The Interlock Module controls spark and the fuel cutoff solenoid. If you have spark then the Interlock Module is probably not in a condition that is prohibiting the starting of the engine.

Did you try a shot of starting fluid? With spark and compression that will allow the engine to start and run for a few seconds.

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Good point on "Through the carb"... I do not hear the click of the solenoid. And no luck on getting it to run briefly using starting fluid.

The Interlock Module must be a part of the display as I can't find a separate unit. And part number isn't coming up as an exact match for a replacement.

See if 12v is present on the fuel shut off valve wire when the key is in the run position. If not, something in the module or key switch is wrong. I wish I knew more about those to help but I don't. If the fuel shut off solenoid wire has 12v, then remove the fuel shut off solenoid and visually check its full operation, key on and key off. Plunger should retract with key on, spring back out when key off. Be sure nothing is blocking the seat of that plunger too.

Sure you have spark? It should pop or run a second or two on a couple of shots of starting fluid if it does have spark.

This from left field. A while ago, not sure where I got it, but a guy had inherited a machine that would not start. Was getting spark from plugs. Turned out PO had installed incorrect plugs, plugs that were specified for the engine but only for engines after a certain point in the engine serial numbers. The plug was way too long for the older model he had.

This would be considered very rare but check your new plugs against the old, be sure the thread depth matches those that used to work. Or try reinstalling the old plugs to see if anything changes.

Ajwingz said:

it will crank but not turn over.

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Normal usage of crank means the engine turns over. Turn over usually means the engine turns over/goes around, but not under its own power. Run means the engine is turning over under its own power.

If you are in Boston, crank means runs really fast (as I recall).

It sounds like the starter is able to crank/turn over the engine, but the engine doesn't catch/run under its own power.

A 4-cycle gas engine needs air, fuel, compression, spark in the right quantity and order to work. Usually, starting fluid will prove that fuel is or is not the issue. Air is usually not the issue. That leaves spark and compression. You typically don't need much compression to start an engine. That leaves spark, which you said you verified. That leaves "in the right quantity and order". I would check compression, valves, timing, probably in that order.

Without some background on this engine such as number of hours, whether there has been any "events" with it, how this problem came about, such as if it was sudden or gradually coming on, it will be difficult to make anything but general suggestions on what to look for.

Frogmore has made some good observations on what to look for and what to check.

One other you can check for free, is whether the flywheel key has sheared. Remove the flywheel nut, and observe the slot in the crankshaft and the slot in the flywheel. They should exactly align with each other. The key fills those slots and sometimes can shear allowing the slots to slip out of perfect alignment. The spark is then not timed to the compression stroke and misfires or total fail to start occurs. Below is a pic that shows what a partially sheared key looks like after the flywheel nut is removed. Notice the two slots are no longer perfectly aligned with each other as noted by the red marks. Remember to re torque the nut upon reassembly it the keyway is OK.