MTD 4P90HU

[zeeter]

Bad battery. So now it cranks but won't start.
So...

Valves adjusted
New spark plug
Refreshed gas
New Solenoid
New battery.

What's next? Fuel line? Have a professional do the valve adjustment?

 

[bertsmobile1]

There are 2 safety circuits built into th engine.
One prevents the engine cranking if it is in gear or the blades are engaged.
The other shuts down the spark should you fall off with the engine running or attempt to dismount with the blades turned on.
So you need to check for a spark.
I use one of those neon tubes that goes between the spark plug and the High tension lead because they glow red & are easy to see.
If it has a cylinder on the bottom of the carb with 1 or 2 wires going into it that is a shut off solenoid which if it is not working will also stop the engine from running.
Hold it between your fingers ant turn the ignition on * off a lot of times confirming it goes on & off every time.

 

[zeeter]

So you're leaning towards it being a spark plug problem? I was thinking that it may be the fuel line, but a spark plug tester is pretty cheap so that'll be my next step.

 

[bertsmobile1]

It is a 15 second test that can save hours mowing the wrong lawn.

 

[zeeter]

Spark plug is good. I also changed the fuel filter. It won't fire at all. I'm afraid to run keep trying it because I'll wear out the battery.

As for the safety features, my experience is that the flywheel won't even spin if I'm not sitting in the seat, so it isn't the safety switch.

 

[zeeter]

Oh - I also tried it without the air filter and cover on, thinking maybe the air filter was bad. No difference. It's like it's not getting any fuel. I tapped on the carb and jostled the lever on top as I've read to do. No change.

This mower is less than two years old. It shouldn't be having these problems. Tomorrow I'm going to adjust the valves again as maybe I didn't do that right.

 

[bertsmobile1]

Try a squirt of starter fliud down the carb , if it fires then the the timing & valves are OK.
Prime suspect becomes the fuel solenoid on the bottom of the float bowl.

 

[zeeter]

Thanks - but I just discovered it's still under warranty and so I'm not touching it anymore. I thought it had a 1 year but it had 2 years.

 

[zeeter]

Sears warranty guy came out. Looked everything over. Inspected the gas, said the problem was that the gas had water in it. I said it was only a couple of months old but he mentioned that 7-11 gas sometimes has too much water in it.

So ok...emptied the gas tank again. Emptied the carburetor. Got all new gas from Exxon. Added some Sea Foam to it. Poured it into the gas canister, went to start. Nothing. Fly wheel spins and spins. No spark.

Called Sears back and they can't get some out to me until August or so, since I cannot take another Monday, Tuesday, or Wednesday off to accommodate their schedule.

 

[Freakdaddy999]

So how did that end up?