John Deere 345 dies out and needs choke to restart

sparky672 · Jul 24, 2015

John Deere 345 (1998) with a Kawasaki FD590V engine (800 hours)

I am the original owner and have always maintained this tractor as per the standard maintenance schedule.

I'm having an intermittent issue and I need to know how to conclusively check whether I have a bad carburetor, or something else like a weak fuel pump.

During mowing only, whether the tractor is under load or not, it sputters out and dies. Then it takes constant choking to get it started again. It has to run a bit while choked before it stays running. Then it runs normal for a few minutes and then dies again. It's like the fuel is temporarily shut off somehow and it only runs until the fuel in the bowl is consumed.

I've had the carb apart and it always seems to run better after this, but within a couple hours the problem returns. There is a new air filter, carb gaskets, fuel filter is not clogged, and there seems to be adequate fuel pressure and flow. The carb has been cleaned and the float adjusted to factory spec; and it runs great in the garage. I've adjusted the throttle and choke plate to factory spec. I only have this issue while mowing but it's not related to load. I can bog in down in thick grass and it runs fine... then later in easy grass, it just sputters out.

I also have a possibly related issue where I cannot shut off the tractor without popping and backfiring. I can't even throttle it down without backfiring. Even if I throttle down very slowly, I still get backfiring and popping.

This video shows the problem as it's happening. You can see how I need to keep choking it before it stays running. Then I can resume cutting for a minutes longer.

https://youtu.be/dljnTozdBMc

I need suggestions and advice before throwing any parts at it. I'm thinking it needs a new carb but not sure... maybe fuel pump?

Thank-you for any suggestions!

Zebrafive · Jul 25, 2015

Try back blowing the line from the fuel filter to the fuel tank. Something is plugging the fuel pickup in my JD 285 and that works for several months for me. I am not wanting to pull and clean the fuel tank (looks like too much work to remove the fuel tank)

sparky672 · Jul 25, 2015

Zebrafive said:
Try back blowing the line from the fuel filter to the fuel tank. Something is plugging the fuel pickup in my JD 285 and that works for several months for me. I am not wanting to pull and clean the fuel tank (looks like too much work to remove the fuel tank)

I'm definitely going to take your suggestion. However, I failed to mention that this only seems to be happening when it's warm. Whenever I try fixing it and test mow at night, the problem never happens. In either case, it could still be an issue related to fuel flow, so your idea is solid. Thanks.

Zebrafive · Jul 26, 2015

Maybe vapor lock? Is there a way to insulate the fuel lines?

sparky672 · Jul 26, 2015

Zebrafive said:
Maybe vapor lock? Is there a way to insulate the fuel lines?

Yes, it's possible. However, the lines are in their stock configuration. All stock heat shields are in place. Nothing has been modified since the tractor was manufactured.

So if it's vapor lock, I'd like to find what's broken, rather than making any modifications.

sal64 · Jul 26, 2015

i had same problem with my jd345,i cant give you any solution because i got tire of it and traded the tractor. i did everything you did then asked the dealer they said change fuel pump so it did that and it didnt fix problem. could it be electrical?

sparky672 · Jul 26, 2015

sal64 said:
...could it be electrical?

I don't understand how it could. The fuel delivery system is 100% mechanical, and it always restarts after some choking. I've also found that choking when it starts sputtering keeps it from dying.

bjr · Jul 26, 2015

If it's got one them anti-backfire solenoids, then look at that. I had one on a B&S that I finally ground the tip off the valve part and then no more problems. bjr

sparky672 · Jul 26, 2015

bjr said:
If it's got one them anti-backfire solenoids, then look at that. I had one on a B&S that I finally ground the tip off the valve part and then no more problems. bjr

This model does not have that.

NCAL · Sep 9, 2016

Did you ever resolve this issue? I am having what seems to be the same problem. At first I thought it was just the fuel pump because I did see it leaking when I could get it running. I changed the pump and mowed for several hours. I suddenly stopped and I found that the only way to start it was to push the choke lever forward and even at that I had to nurse it back to the garage. I was beginning to wonder if I got a bad pump.