Quote Originally Posted by lmgtexas View Post
I purchased a new kubota Kommander zero-turn mower (ZG127E, 54 inch) in February 2014. The unit ran great the first spring/summer. I use it mainly for mowing the 2 acres around our house and for cutting along the fence lines on our 40 acres. The second season (2015) I began to experience a similar problem to you - that is after mowing for an hour to an hour and a half, the mower would begin to surge and slow down as if it wasn't getting a steady supply of fuel. Then, if you tried to stand up and step off the unit, the mower would just shut down (as if you hadn't set the safety brake). Then you would have to wait for some time before you could get it started again. The dealer I had purchased it from was no help (very poor service and parts group), so I finally trailered it to a more distant dealer in April of this year before the "mowing season" started. He diagnosed the problem as an engineering group flaw with the fuel switch/line coming out of the fuel tank. Apparently the opening is way too small so any debris or contaminant will cause a fuel flow problem. Additionally the brake switch was defective. The replacement of the brake switch (under warranty) solved that problem. Cleaning out the fuel line solved the other problem. Kubota really hasn't addressed the design issue with the fuel line which has made me reconsider my decision to purchase a full-size (60 horsepower) Kubota tractor. I believe Kubota may have damaged its tractor reputation with the addition of a poorly designed zero-turn mower. It hasn't helped that the dealer in Taylor, Texas, where I purchased the zero-turn mower has a fairly lax attitude about servicing these units. For now I will stay with my Mahindra 35/25 tractor and when I decide to upgrade will keep the smaller Mahindra and just add a larger Mahindra tractor to my inventory.
Quote Originally Posted by lmgtexas View Post
An update on my earlier post about the problems with my Kubota Kommander. Now, a year later, I still have my Kommander and through trial and error have developed a protocol that I go through to keep the mower running. First, I changed from Kubota oil to fully synthetic Mobile 1. That appears to let the engine run a bit cooler. Next I always pull the air filter before using the mower and make sure I tap out as much loose debris that has collected on the outside of the filter. Of course checking the oil level and filling the tank with fresh fuel is a regular step. Finally, before using the mower, I disconnect the fuel line from the fuel filter and physically blow on the fuel line until I can hear bubbles in the fuel tank. That way I know I have "blown out" any debris that might have collected in that problematic, engineering problem with the valve coming out of the fuel tank. After that I can generally mow for as many hours as I want or need to until I have to re-fuel. Then I allow the mower to cool down before refueling. After the unit has cooled down sufficiently, I go through the same "start up" procedure again. Before putting the mower away, I always using a blower to blow off all grass and other debris so the mower is ready to go for the next day. Note, this mower is garaged, and is kept under a special tarp! I hate to have to do all that to keep a $5,400 mower operating properly, but I do what I have to. No more Kubota products in my future. I have an old Mahindra 3525 tractor that I'll be keeping even after I upgrade to a 60-horse power model (Considering I have a 10-year old Snapper riding lawn mower that runs flawlessly year in and year out without all this pampering, and the Mahindra is equally reliable - so much for Kubota being the "Cadillac" of field equipment!)
We have a 2016 Kommander Z121 which developed a mysterious fuel starvation problem (symptoms similar to those you describe). A solution mystified the dealer - fuel was fresh, inline filter and lines clean, vacuum fuel pump operating, carburettor clean - yet the machine would miss and cut out when mowing. After much investigation (which included completely draining the fuel tank) I found that the flexible fuel pickup tube which is mounted in the top of the fuel tank was square-cut at the bottom end. With the engine running, the flexible fuel pickup tube would suck onto the bottom of the plastic fuel tank causing fuel starvation. This was easily resolved by cutting the bottom end of the pickup tube at a 45° angle (without shortening the overall length). The mower has run flawlessly ever since. I honestly believe that this is a problem that many Kubota owners have experienced and which the dealers have been unable to resolve, resulting in these mowers copping a fair bit of undeserved flak.
