Defective Kubota Mower. Help!

[rwhitmire]

I purchased a zero turn Kubota lawn mower in 2016. Before the end of the first season, I noticed the engine was surging. At the beginning of the second season, I had it serviced. They cleaned the carburetor and switched spark plugs. It was better for a while, but the surging returned and was worse.

I had it serviced again. They cleaned the carburetor again and returned it to me. It was better for a few weeks until once again the engine surging returned. I sent it back once more. At this point, they completely replaced the carburetor. The mower ran well for a few months, but was difficult to get started.

Last weekend, the mower was unable to start. The engine turns over, but acts like it's not getting any gas. I know a bit about engines and machinery, but I don't have the time to be constantly repairing a machine that is practically brand new.

All work done so far has been done under warranty, but there's an $80 charge for pickup and delivery and I'm typically without my riding mower for 2 weeks at a time which means I get to mow an acre of land with a push mower. The engine only has 37 hours and it's spent more time in the repair shop than it's spent in my garage.

I want a replacement. The dealer tells me to call Kubota, Kubota tells me to call the dealer. Has anyone had a similar issue? I'm really not sure what to do with the $5000 piece of junk sitting in my garage.

 

[85Hokie]

Sounds to me that fuel is being restricted - as the load is placed on the machine, the governor is trying to ramp up the rpm's and that is causing the surge.

I would take all the gas out, clean the tank, change any gas filter, and "blow" back through the hose to the tank.

Something is restricting the flow - if in the carb, something like a small piece of trash is stuck in the orifices/jets.

I would demand they get it corrected, since they have not fixed it at all.

Dumb question......what does the porcelain on the plugs look like?

 

[BAP]

I am Seconding what Hokie said. Sounds like there is not enough fuel getting to the carb. very common to get a piece of something in the tank or even some sludge that moves around and restricts flow from time to time. Of course, if they have already cleaned the fuel tank and lines, then that rules those items out.

 

[RCW]

Do you use ethanol gas, or ethanol-free?

 

[rwhitmire]

I use ethanol free gasoline only. The dealer called me back today. They contacted Kubota who told them they had to deal with it and the dealer is unwilling to "take on the burden of a trade or replacement" but are "happy to continue assisting with warranty work and repairs."

I'm spending a ton of money on pickup/delivery surcharges and I'm without a mower for huge chunks of time which means I get to push mow an acre of grass every 5-8 days. I had to go purchase a push mower this summer as a backup to handle my lawn while the $5000 mower sits in the repair shop. I know a little bit about small engines and maintenance, but I don't have the time, tools, or desire to be constantly repairing this thing myself.

 

[Freeheeler]

Check the vehicle lemon laws in your state and see if they apply to mowers. If so you could go thru those channels for a replacement.

 

[BAP]

Do you know if they have actually cleaned the whole fuel system?

 

[100 td]

And if it's crap in the tank/lines, externally introduced (meaning grass etc), you may be up for a big bill.

 

[lugbolt]

Well....what mower is it? I have a suspicion....but let's hear what model it is?

 

[Dave_eng]

A simple way to narrow down the source of the problem is to make up a temporary fuel supply directly to the carb.

Some have had success with squeeze type mustard bottles. Remember, you are dealing with gasoline and not diesel so fires are a serious concern.

If it runs well on the temp fuel supply you now have narrowed down your problem.

Dave

 

[Vacula]

Surging carburated small engines are fixed by starting at the tank and going forward. Check for a plugged up air filter first! Next, is the fuel cap plugged or blocked? Disconnect the line at the tank! Good flow? Disconnect at the carb or if pumped, at the inlet of the pump. Good flow? Next after the pump. Good flow from the pump? If all things point to the carb and if the carb is equipped with exposed, actual needles valves that are not CA carb compliant, remove them and shoot some carb cleaner in them and reinsert to the prior or better yet, factory setting. Fixed? Better? If not, pull the carb. Were the carb bolts loose? Clean the carb and more importantly, check the float against the factory recommended settings. Use your measured wire gauges and check the orifices for restrictions. Cleaners can only do so much in these very constricted openings. Before bolting it up, look for cracks on the intake and cracks on the air filter risers and nozzle. These plastic pieces are easily broken if torqued too much allowing crap into the carb in a short amount of time. Too often, dealerships spend little time looking for these things. The assumption is "whatever" and they dive in, do a fix, bolt it back up and release it back into the wold without doing what you should do as a good practice.

 

[BAP]

Surging carburated small engines are fixed by starting at the tank and going forward. Check for a plugged up air filter first! Next, is the fuel cap plugged or blocked? Disconnect the line at the tank! Good flow? Disconnect at the carb or if pumped, at the inlet of the pump. Good flow? Next after the pump. Good flow from the pump? If all things point to the carb and if the carb is equipped with exposed, actual needles valves that are not CA carb compliant, remove them and shoot some carb cleaner in them and reinsert to the prior or better yet, factory setting. Fixed? Better? If not, pull the carb. Were the carb bolts loose? Clean the carb and more importantly, check the float against the factory recommended settings. Use your measured wire gauges and check the orifices for restrictions. Cleaners can only do so much in these very constricted openings. Before bolting it up, look for cracks on the intake and cracks on the air filter risers and nozzle. These plastic pieces are easily broken if torqued too much allowing crap into the carb in a short amount of time. Too often, dealerships spend little time looking for these things. The assumption is "whatever" and they dive in, do a fix, bolt it back up and release it back into the wold without doing what you should do as a good practice.

Well worded and very good advice Vacula!