Kubota RTV900 stalling

[jpaeye]

I live in Northeast Ohio where winter has been a little rough this year. I have a 2006 RTV900 purchased used in the fall (138 hrs) which I use to plow snow. Plowing has become a huge nuisance because of its increasing tendency to occasionally run rough then stall. I will say it started this behavior before winter, but it has worsened. The last time I plowed, I was out for about one hour and it stalled 8 times. Generally, it starts to cough and spit, loses power, idles roughly after I leave off on pedal to remove all load, but then "catches its breath" and starts to run well again. The stalling is becoming more frequent, though. sometimes it takes 4-5 tries before it restarts. I need to get this fixed before I need a new starter as well. I notice this behavior usually when going up hills, but not major grades at all.

I changed all filters and fluids in fall, as well as air cleaners. I recently changed the fuel filter thinking (hoping) it might contain a chunk of ice--no dice, it looked good. I went out today to take off diesel tank to inspect its innards for obstructions or sludging/gelling of fuel but my siphon pump would not work correctly. I also removed the spark arrestor.

I think the issue is likely a lack of fuel, whether from obstruction in the tank, or perhaps pump or injectors.

Anyone ever come across this behavior with their Kubota RTVs? Hoping for some insight/direction, and perhaps like experience.

Also, previous owner did NO routine maintenance at all. That's right, didn't even change motor oil and filter.

 

[gobraphil]

did you replace the fluids with the SUPER UDT instead of the standard UDT? When the temp gets below 30, the viscosity of the udt gets really high (thick) and it is harder to pump.

How does it run when the outside temp is warmer?

The super udt viscosity doesnt vary as much with the temp, so it will definitely help. I am replacing mine soon with the super and i live in alabama.

 

[jpaeye]

Yes, super UDT in transmission now with fluid change in fall. This started back in the Fall when it was warm, and has gotten worse this winter. I will try to get another siphon pump and pull the tank this weekend. If that is OK, it probably is looking like an expensive repair and perhaps even a trip to the dealer.

 

[stuckinnj]

Trans fluid will not affect the performance of the engine for the condition you describe. If the fluid is too viscous the trans performance will be poor i.e. difficult to move or shift. The engine will only be affected by the load/strain of the attempting to move the fluid.

With that said, if the engine is coughing and stalling, it suggests that it is possibly starving for fuel. That could mean and failing fuel pump or crap fuel. Suggest you drain the tank into a clear container. Let it sit for a while and see if the fuel/fluid separates. Most likely, you will find water that is sitting in the bottom of the tank. When you are using the RTV, it sloshes around and gets picked up by the pump pick up tube. The result is, runs okay for a bit and typically when under load, the engine starts to starve for combustible material. Water doesn't ignite real well.

After you drain and clean the tank out, I suggest fresh fuel w/conditioner. Read the container for the proper mix ratio. Don't go overboard with the conditioner. Too much is not a good thing in this case.

Good luck.

 

[jpaeye]

Thanks, stuckinnj, those are my thoughts too. Hopefully not a fuel pump but possible (intermittent nature makes it less likely), possibly bad fuel, possibly obstruction in the tank. Thanks again.

 

[atgreene]

Have you treated your fuel with Power Service? Sounds like you're gelling slightly. You won't necessarily be able to see it in the filter, treat it regularly with white bottle Power Service, also, next time it does it dump some red bottle Power Service in and see if it clears up.

Other than that you may have a bad seal on your fuel filter or a leaking pick-up line on the fuel system. Check all the connections closely if the PS doesn't do it.

 

[jpaeye]

Thought I would update everyone. Drained the entire fuel system over the weekend, removed and cleaned tank. Put old fuel into an empty clear water bottle, doesn't appear to be gelling or contain water. Put fresh fuel in RTV900 and it runs like new.

I think I got a bad batch of diesel at some point. Have always used power service additive, but it can't make up for bad fuel. Will never buy diesel from the corner station anymore, will drive another 10 miles to the truck stop near the turnpike. I would expect fuel to be fresher there (I hope).

Thanks for all your help and suggestions.

 

[TOMMYHPX4X4]

what about the filter did you change the fuel filter too. by draining the tank you could have backwashed the filter and the filter is semi clean now thats why it's runnin better.

 

[R_Walter]

There's a one-way check valve in the system that keeps the fuel from draining back to the tank on shut-down. If that valve fails, then the engine will stall until you crank and crank it to pull more fuel from the tank. Just a thought.

 

[plasticpaddy]

Bought a used 2006 RTV 900 last year for light use on 5 acres. Ran retty good but would stall out/cough occasionally mainly on steep trails going downhill and most of the time run fine. Replaced fuel filter and fuel pump to no avail. Finally pulled the tank this weekend. Found abut a 3 inch piece of grey gasket cement in the pickup tube. Picture attached.