X 300 stalls after 10 minutes

[chazdo2]

My X300 stalls after anywhere between 10 minutes and 30. In a short period of time starts right up works fine and it stalls again after a short period. I pulled the plugs and they are dry each time look to be burning well. Any help out there?

 

[Diggin It]

When it stalls, does it just shut off like an electrical issue, or does it get weak and quit like a fuel issue? If the latter, check fuel flow, lines, filter, and the gas cap vent. There have been quite a few instances of those vents getting plugged up over time. Fuel being drawn into the engine creates a vacuum in the tank if the vent isn't breathing.

I've also seen reports of ignition coils getting weak and causing stalling.

 

[4570Man]

Bad coil. You can test the theory with a spark tester or just ground the plug against the head and turn it over while it’s hot and won’t run.

 

[chazdo2]

it just quits like somebody turned the key off. The cap is new and the fuel filter is full of gas. The vent screen on the fuel pump is clean. When it quit eachg time I pulled the plugs and they were dry as a bone. Could the back fire solonoid in the carb be acting up? Is there a static test for the coil? Ohm check?

 

[4570Man]

The only test I know of for a coil is if it sparks the plug or not.

 

[buckeyefarmer]

Loosen the gas cap and make sure it's not pressure from not venting.

 

[PILOON]

Loosen the gas cap and make sure it's not pressure from not venting.

My thoughts also!

 

[buckeyefarmer]

My thoughts also!

Mine does it, stalls in about 10 min.

 

[Diggin It]

However, he says:

it just quits like somebody turned the key off. The cap is new

Most people can tell the difference between one shutting off due to electrical or ignition issues and one losing power, sputtering and dying of fuel starvation.

 

[buckeyefarmer]

Mine does it, stalls in about 10 min.

And acts just like you turned off the key..

 

[tomplum]

There are 2 coils, so if you dropped one it would still run. It could be the ECU. It is located under the top of your dash. Try tapping on it as it warms to see if it will kill or at least miss.

 

[chazdo2]

Thanks for all the info. I brought a plug wrench with me as soon as it quit I pulled the plugs and as I said dry as a bone. Ill try again today with a spark tester and do the same thing immediately when it quits. It has a brand new cap and the counter guy said the old cap was good but the owner bought a new cap anyway. I have a few spark testers maybe I can rig both sides up with them mow with the hood off and see if the spark dies. It seems to give ya about 2 seconds before it dies maybe not that much.
I had a problem with another X300 that wouldn't start. I disconnected the black wire that kills the coil and it started right up. I replaced the ECU and now it runs perfect. Could the ECU be killing the carbs anti backfire solenoid shutting off the gas or killing the coils? Its an expensive part to shotgun and be wrong!

 

[tomplum]

The ECU does control the solenoid. Anything that controls the solenoid can be an issue, if it is really a heat related issue- could point back to the ECU. Does the time extend itself with the hood off? It too is fairly common for the pick up tube in the fuel tank to get partially plugged with grass and debris which causes an intermittent stall when the pump can't overcome the debris. Pine needles and strands of grass are the worse for this. Cleaning the fuse block and switch terminals with CRC should be done anyways. I'm not sure if you are servicing mowers for living, because if you do- you should have an ECU in stock.

 

[Diggin It]

It has a brand new cap and the counter guy said the old cap was good but the owner bought a new cap anyway.

I had a problem with another X300 that wouldn't start. I disconnected the black wire that kills the coil and it started right up. I replaced the ECU and now it runs perfect.

Are these your own personal machines, acquaintances or are you working in a shop somewhere?

You really should try opening the gas cap, even if just for giggles.

 

[chazdo2]

Are these your own personal machines, acquaintances or are you working in a shop somewhere?

You really should try opening the gas cap, even if just for giggles.

Plot thickens. Mowed with it for about 40 minutes with the cowl off so I could view the spark testers when the machine shut down. Never stalled out today. Maybe the extra cooling made the difference? I know coils can fail sometimes when hot. Maybe it means nothing? Ill test again tomorrow to see if it will stall again. Ill do more with the cowl off and if it doesnt stall Ill put it back on and see what happens. Ill keep ya posted! And thanks a lot!!!!

 

[beenthere]

If you think it isn't air-cooling enough, check for mouse nest around the engine..

 

[chazdo2]

No nests or anything near cooling fins engine is really clean. Ill mow again tomorrow to see what changes.

 

[Kish318420]

Actually you need to pull any tin, because the critters can get up inside the cowling (underneath it)

 

[beenthere]

Neighbor lost his engine in his Simplicity from a mouse nest.. he too thought "no way".
But cooked one cylinder. But now he is a Deere owner and very happy.

 

[chazdo2]

More I think about it I better pull the recoil and engine tins at the very least to rule it out. Thanks!! I never considered it because the engine looks like it came out of the show room!!! I will get back to you guys after todays cleaning and testing. Again thanks for all the help!!!!!!