ignition system coil or plugs...... or plugged gas-cap in the fuel tank....
does it restart right afer it happend?... try loostening the cap a bit next time see if the problem goes away (may need to secure the cap so it doenst vibrate off..... and the cap - when you cleaned it - did you get inside?... are you certain it "can breathe"?...

otherwise, change the plugs... if that doesnt help, then test the ignition - right after it happens - check the strength of your spark....

 

ignition system coil or plugs...... or plugged gas-cap in the fuel tank....
does it restart right afer it happend?... try loostening the cap a bit next time see if the problem goes away (may need to secure the cap so it doenst vibrate off..... and the cap - when you cleaned it - did you get inside?... are you certain it "can breathe"?...

otherwise, change the plugs... if that doesnt help, then test the ignition - right after it happens - check the strength of your spark....

Good point on cleaning the gas cap. All I did was push a paper clip through the hole. I wondered if that would be sufficient. Is there more to it than that?
No, it doesn't restart right away after it happens. I have to wait 10-15 minutes, sometimes longer. The plugs on there are brand new. I've only used the mower 5 or 6 times since changing them. I did wonder about the coils too, but you're the 3rd person now to tell me to check the gas cap vent.

 

the gas cap is easy to check... you can loosen so it can breathe without the vent itself.... it but tape it down or secure it so it doesnt come off... then see if you can go longer than 10-15min....

 

If it does not start right away after loosening the cap, that is not it...if it won't start for a short while...you likely have a coil problem...or mouse nests under the shrouds causing it to overheat

 

keep in mind that when you run the gas dry, it will take several seconds of cranking to refill the carb before fuel is once again delivered to the intake....

 

Check the fuel filter, see if there is gas in it or not. There is never a lot in there, but you should be able to see if it is wet or not, when the problem occurs again. You can also use carb cleaner/starting fluid/a small amount of gas in the carb throat to see if lack of fuel is the issue or not.

The other thing is spark. Get a spark tester tool so you can see the quality of the spark. Try the tool when the engine will run, so you can see what is normal.

If it is not a fuel issue, it is likely the coil, since when they get too hot they can short and stop providing enough voltage for a spark.

 

Blew out gas cap vent and then sealed it on tight...same issue. Loosened the cap...same issue. Tried with no cap...same issue. Once it stalls I can't start it again for about 10 minutes. So it sounds like it might be a coil issue?? BTW, thanks for everyone's help.

 

Once it stalls I can't start it again for about 10 minutes. So it sounds like it might be a coil issue?? BTW, thanks for everyone's help.

I would -guess- a coil. A longshots would be the voltage regulator overheating. I had similar issue on a car and that was the fuel filter. If you stored gas in it over winter, it may still be clogging up the filter or there is water in the tank. But I would still guess the coil first.

 

After it stalls try a shot of starting fluid. If it fires up, then you have a fuel issue. Clogged filters, weak pump, vapor lock?
If it still won’t start, then spark is the issue. Coils are suspect.

 

yea - so next time it happens - remove a spark plug and check for proper spark.. if you see nothing - you know the issue.
if you see spark but weak - judgement will have to play a role...

 

I spoke to a local JD mechanic. First suggestion was fuel cap, second was fuel solenoid. He said that considering it's a 2 cylinder, if one coil was bad the other would still work. The odds of both failing at the same time are slim. If he were betting and without looking at it, he'd say it was a fuel issue. I'll continue the process of elimination and report back. Thanks everyone.

 

Fuel is the easiest thing to check. Look at the fuel filter. If you can't see through it, you need to replace it. Is there fuel in the bowl?

Try gas/carb cleaner/starting fluid in the carb. That is really easy. Does it run for a few seconds? If so, it's not getting fuel the way it should. Could be the fuel shutoff solenoid is not working sometimes.

One or both coils not working are also a possibility. The spark tester thing makes it less shocking to tell, but the old fashioned way of just holding it slightly away from the plug also let's you know if it is getting spark at all or not.

Since you took off the air filter to test that it is getting gas, you have eliminated that as an issue.

If it still doesn't start, then it has something very unusual, and probably expensive, but that is not very likely. So check the easy stuff first.

 

Started it back up after several idle hours and I only got about 3 minutes of use. Filter is clean and full of gas. I shot starter fluid in the air intake and it did run for a few seconds. Fuel solenoid? Something else to throw out there...I replaced the fuel pump myself a couple months ago. It was very straight forward, but is it possible I did something wrong? Both hoses are correct and the gasket is on. So I don't know what I could've messed up, but I at least wanted to mention that.

I also should add, it seems like I'm getting less and less time with it before it stalls.

 

Where did you get the fuel pump? OEM?

 

Amazon. Not OEM. Holdwell is the brand.

 

Hmm. Maybe verify that pump actually works then. Third party parts are not always the best ...

 

It did start doing it last season with the old pump. Granted, it wasn't nearly as much as now, but still doing it.

 

I have heard said before “The last thing you fixed will be the next thing to break”

 

If you still have the old one, slap it back in. See if it makes a difference

 

Unfortunately not.

 

If the filter is full of gas, the pump is probably working well enough. Next step is the carb. It might have an obstruction somewhere that is causing it to not work right. Test the solenoid for sure.

 

Had the fuel pump replaced not sure what brand, but cost $144 . It still runs for a short time and starts surging[ then dies. Checked fuel filter - it was dry. Sprayed some "tune-up" stuff in the throat of the air cleaner housing, helped until it used that up, then back to surge and die. Is there a filter in the tank ?

 

The first LX models sometimes had gas cap vents that would block easily. Remove the gas cap and see if the engine keeps running. If so, take a pin and clean out the hole in the middle of the gas cap. I do not know if the tube in the tank has a filter, but you can remove the fuel filter and blow on the tube that goes back to the tank to see if it is clogged. Also, check the clamps on both sides of the fuel filter. If they are not tight, air will leak in. I use the screw type hose clamps to get it tight.

 

I know this is an old thread but...I bought this same tractor, LX178, with the same problem. Previous owner had it into the dealer. The dealer replaced everything from the fuel filter to the carb including new OEM fuel pump. Same thing happened, run 30 mins and die, let sit 30 mins start and die after 20 mins etc. So they bought a new tractor and I got a deal. When I got it home I started it up and let it run and watched the fuel filter. Tiny bubbles were coming from the tank side and would fill the filter with air and vapor lock the fuel delivery system. $5 of new fuel line from the filter to the pick-up tube in the gas tank and she runs for hours. With the age of these tractors the fuel lines get hard and crack and don"t seal. The dealer should have gone a little further with the parts cannon. This tractor has the liquid cooled twin cylinder Kawasaki engine. The coils are mounted on the side of the engine block, very visible and easy to get at and less likely to heat up so quickly. It also does not have a fuel shut off solenoid. I use this tractor almost every week and is one of my favorites. The bonus was that it has a Pirana deck. I know this was a little long but it's one idea that a lot of people wouldn't think of because in order to replace the fuel line all the way to the tank you have to pull the fender pan.