Fuel issue with Cub Cadet Commercial Z turn...

[varmint]

I've been happy with my slightly used 48" Commercial Z turn with the steering wheel I bought a couple years ago- really cut my mowing time in half. Other than a deck belt tensioner spring coming loose, which was easily fixed once I figured out what had happen- a pin came out of the fastening clip, no problems.

But recently, when I use the left side fuel tank, it'll run for a while, then die. It's a lack of fuel issue. Works fine on the right side tank. I tried loosening the cap, thinking maybe it was not venting, but that's not it. Both tanks are fairly full, same new gas in each. When I first start it, cold, it'll run maybe 15 minutes on the left tank before dying. Restart on the right tank, runs fine. Switch to the left tank, runs for maybe 5-10 minutes, then dies again. Before I start investigating the fuel pickup, the lines and so forth, thought I'd ask if anyone has any experience with this problem? It'll give service with just the right tank, but not ideal. Thanks.

 

[GBHRPS]

varmint,

Sure sounds like the tank isn't properly vented, but if you're certain it is, then its either the switch tank valve or the fuel line from the tank to the valve. Nothing else makes sense!

 

[BukitCase]

Not familiar with that model ( I have the RZT50) - does yours have separate fuel filters for each tank, or one common one? Symptoms sound like a partially clogged filter to me... Steve

 

[varmint]

Not a vent issue- cap removed and it still will die. Only one (new) fuel filter. More curious, yesterday it ran fine on the left tank, so whatever it is or was, it is at worst intermittent.

 

[BukitCase]

Only other thing I got - if the left tank is the ONLY tank that may (or may not) have the problem, I would check inside that tank (light, mirror, whatever you can see with) for anything partially submerged (that is NOT supposed to be there, that is) - I had this problem with my backhoe a few years ago - ran fine most of the time, but when I got "frisky" with it, about half the time it'd die just like pulling the fuel shutoff (diesel) - drove me nuts, 'cause I could let it sit for maybe 15 minutes, start it and it'd be fine (sometimes for days or weeks)

In my case, some sort of algae had gotten together with some rust flakes and formed what looked like a miniature "kombucha tea" mushroom - with the rust flakes, the "mushroom" was magnetic enough I used a small rare earth magnet on a wire and fished it out.

What apparently had happened was that the "mushroom" would wander around in the tank til it got over the fuel outlet, then get sucked down and form a CHECK VALVE - if I tried to re-start immediately, NO GO - but wait a while and the lack of suction would allow the "check valve" to float up.

Yours being gas, this still might be able to happen, but maybe with something that got soaked in gas enough to partially submerge enough to still form a "check valve" when it gets close enough to the fuel outlet...

Yeah, I admit it's unusual, but my experience says it CAN happen; might be worth taking a hard look inside YOUR tank if you get desperate enough :2cents: ...Steve

 

[mike48130]

Could be 2 things, the pickup in the tank is dirty. I have seen this on several tractors where the screen gets clogged and limits the fuel flow and stalls due to starvation.

On my Toro, they use 2 check valves to keep the 2 tanks from back feeding. You could have an issue with the check valve being bad or clogged. Or if you have a valve that switches between the 2 tanks like the Exmark's do, them maybe that valve. is bad or clogged. I would pull the line to that tank where ever it tee's in, and put some air pressure on it and see if it clears up.

 

[Recapper64]

I've been happy with my slightly used 48" Commercial Z turn with the steering wheel I bought a couple years ago- really cut my mowing time in half. Other than a deck belt tensioner spring coming loose, which was easily fixed once I figured out what had happen- a pin came out of the fastening clip, no problems.

But recently, when I use the left side fuel tank, it'll run for a while, then die. It's a lack of fuel issue. Works fine on the right side tank. I tried loosening the cap, thinking maybe it was not venting, but that's not it. Both tanks are fairly full, same new gas in each. When I first start it, cold, it'll run maybe 15 minutes on the left tank before dying. Restart on the right tank, runs fine. Switch to the left tank, runs for maybe 5-10 minutes, then dies again. Before I start investigating the fuel pickup, the lines and so forth, thought I'd ask if anyone has any experience with this problem? It'll give service with just the right tank, but not ideal. Thanks.

I realize this post is over 4 years old. I have The Cub Cadet ProZ 500. Same issue. The first time I followed the dealers' recommendation and blew air through fuel line. I work fine for the rest of the day, (about 6 hours of cutting) Next week same thing. Left tank went. Then right tank after about an hour. It was under warranty. Took it back to dealer. Worked fine for rest of cutting season 2021. Then just last week started again, 2023. I am now researching how to remove tank and see if it is just a tube laying in bottom of tank. If so, I have (2) 1/4 Small in tank Fuel Line Filters for a snow mobile (Replacement Fuel Filter 7052037 7052081) That I am going to put on the line and see if this works. There was NO trash in fuel filter.
I have used/ using a John Deere lawn tractor for since 2009 and never had issues with trash getting into tank. The fuel openings are the same dimensions.