2016 X310 won't start

[TomfromMaine]

I am a former ASE-certified auto mechanic. I know my way around engines, but this one has me stumped. The lawnmower stopped while mowing the lawn.

This is what I have done or checked:

I have gas, fuel pump works, carburetor solenoid works, air filter, and gas filters are clean, installed a new battery, a new EUC, both sparkplugs fire and shorting the seat safety device didn't work. The plugs are dry, but the machine will start with starting fluid. Disconnecting the black kill wire didn't work. All fuses work.

In the past, I have jump-started the lawnmower and recently discovered that will blow the ECU, so I replaced it. Is there anything else jump-starting the lawnmower will kill?

What can I do or check next?

Tom

 

[slomo]

The plugs are dry, but the machine will start with starting fluid.

One clue there. She is thirsty. Carb cleaning and or fuel system cleaning time.

Dump and flush out the fuel tank/s. You want them spotless inside. Blow out with compressed air. Install ALL new fuel lines.

How do you know the carb solenoid works? Do you have a clear float bowl on it? Get a small bolt the same thread pitch as the solenoid. Use it for testing to 100% rule out the solenoid.

Pull the kill wire/s off the ignition coils. Should run till you drain the tanks out. That is unless you have other issues.

You need good fuel flow AT the carb inlet. Drain into a glass jar so you can watch it. Or a mower can and empty the tank dry. Should drain out freely. Or if it stops you need to clean the tank out.

Don't buy a new carb off amazon or epray.

Start with the basics. Compression, air and fuel then spark. Easy right?

 

[TomfromMaine]

Thanks. I did that when checking the coils. All looked good.

 

[TomfromMaine]

I think the solenoid works because I hear it clicking when I turn the ignition on. However, I know a clicking solenoid doesn't mean it is opening the valve.
How do you test the carb solenoid? I guess the small bolt replaces the valve the solenoid pulls down and you can see the bolt move, correct? I guess that can be done on the machine and will try it now.

Thanks,

Tom

 

[TomfromMaine]

Well, now I am not so sure the carb solenoid is working. I thought I heard it click but don't hear it now. Didn't try the bolt trick until I figured out how to remove the solenoid.

 

[TomfromMaine]

OK, I removed the solenoid, cut the plunger off, reinstalled it, and still no start. I think the plunger is held in the up position with a spring. Energize the solenoid, and it pulls the plunger down to let fuel flow, correct? If there is no plunger, fuel should flow.

What are your thoughts?

 

[bertsmobile1]

Pull the rocker covers and check the pushrods are in place and the valves are working.
I like to pull the carbs off leaving the fuel lines inplace turn them sideways and blow air through them to make sure the carb is actually aspirating fuel
Now I am confused here.
In your original post you mantioned an ECU wich is only found on fuel injected motors and in this post you are talking about carbs
What do you have ?

Finally JD put out a very comprehensive service manual for your mower which includes over 200 pages on the engines alone and around the same on the mowers electronics .

 

[TomfromMaine]

Hi, Yes, the lawn tractor has a carburetor and an ECU (Electronic Control Unit) p/n AM141075. I bought it new from a JD dealer for $110.
I just bought a carb solenoid and two coils from Amazon. The solenoid prevents backfires but costs $200 from JD. The spark tester shows an orange/red spark, a low-power indicator, so I bought two coils. The JD coils are $124 each, but the aftermarket coils were $24.

 

[slomo]

Here we go shopping at amazon and epray. I can't help with non OEM parts.

 

[TomfromMaine]

I agree; OEM parts have the same quality as the mower and are the first choice. However, when JD charges $200 for a carb solenoid, and Amazon has them for $24, I'll go with the $24 variety every time. At 12% of OEM, I can buy a lot of solenoids.