Sidekick RTV-XG850 backfiring / loss of power

[Sidekick]

this machine is way too expensive for all of us to just write off the problem. threads like this are going to crush the resale value on these machines as Kubota has completely bailed on us.

I doubt Kubota cares about resale value. They make a ton on replacement parts and service. I have lost confidence that they actually care about what they sell and solving customers problems with improperly advertised machines. I was getting ready to replace the BX with something bigger this year and it definitely will not be Kubota anymore. Just like when I bought the Z726 last year. I only bought Kubota because I thought they would stand behind what they sell. That turned out being a mistake. I won't make that again
It seems like Kubota wanted to jump in the gas UTV market without much thought or investment by going with a discontinued Subaru engine and some RTV parts. They developed a machine that is not good for smaller homesteads with the engine and belt warm up requirements that can cause serious long term reliability issues. Then on the other hand for large properties this machine is not fast or nimble enough. It is marketed for both applications and not really good for either of them in my mind. Seeing many used low hour Sidekick for sale doesn't make sense because most Kubota buyers buy with long life expectations from Kubota products.

 

[Sidekick]

Since it is a pricey machine, someone should post the make/model info of the Subaru engine into Google to look for 'drop in replacements'. If Subaru didn't make that unit specifically for Kubota, other 'things' may have same engine,see what those guys did to swap it out.

From what I have found this was just an engine Subaru was developing when they shut down the small engine operation in 2017. Seems like Kubota grabbed it at the fire sale. There is no one left at Subaru that knows anything about it I am finding.

 

[lugbolt]

re: One other thing that has me wondering is if this machine is any good for plowing with all the special instructions about not stop and starting it.

hmm, if Kubota sold you a Kubota plow for your Kubota, then the Kubota IS designed to use the plow ! Use it as required to get rid of the 'white'.

A kubota tractor is better fitted for plowing snow.

 

[GreensvilleJay]

hmm, wonder if there's any money in supplying a 'drop-in' replacement engine kit ? Complete engine, adapters, wiring conversion, etc.? Would sales be 50, 100 or 1,000 kits ?

 

[PoTreeBoy]

hmm, wonder if there's any money in supplying a 'drop-in' replacement engine kit ? Complete engine, adapters, wiring conversion, etc.? Would sales be 50, 100 or 1,000 kits ?

I had a little experience with a 400 at a non-profit. The 400's had an injector problem, but you had to buy a 'matched' injector and controller at about $1,000. SGOTI had found a Subaru auto with compatible injectors, had to buy a set of 4, and was selling the others. I thought about retrofitting a carburetor on it.

Anyway, how can gas get into the crankcase? Seems like it would either be bad ring seal or crankcase ventilation. Ventilation could probably be disconnected. I wonder if they fit the rings too loosely since it is air-cooled, or bad ring design. Has anybody tried a leak-down test?

 

[mikester]

I doubt Kubota cares about resale value. They make a ton on replacement parts and service. I have lost confidence that they actually care about what they sell and solving customers problems with improperly advertised machines. I was getting ready to replace the BX with something bigger this year and it definitely will not be Kubota anymore. Just like when I bought the Z726 last year. I only bought Kubota because I thought they would stand behind what they sell. That turned out being a mistake. I won't make that again
It seems like Kubota wanted to jump in the gas UTV market without much thought or investment by going with a discontinued Subaru engine and some RTV parts. They developed a machine that is not good for smaller homesteads with the engine and belt warm up requirements that can cause serious long term reliability issues. Then on the other hand for large properties this machine is not fast or nimble enough. It is marketed for both applications and not really good for either of them in my mind. Seeing many used low hour Sidekick for sale doesn't make sense because most Kubota buyers buy with long life expectations from Kubota products.

I feel your pain. I'll take it off your hands and give you CDN$5K for the machine as-is if you deliver it.

 

[GreensvilleJay]

I wondered about the gas in crankcase for months...thinking it HAS to be loose rings/lousy valves. Very familiar with riding mowers with 'over full' dipsticks..... Gas tank is high, carb is low, gravity 'sucks' gas into carb,past 'anti dieselling solenoid', into cylinder, past rings, into crankcase/sump.
This Subaru engine though is fuel injected, seems everyone can smell LOTS of raw gas which is a huge 'red flag' that something is seriously wrong.

 

[Sidekick]

hmm, wonder if there's any money in supplying a 'drop-in' replacement engine kit ? Complete engine, adapters, wiring conversion, etc.? Would sales be 50, 100 or 1,000 kits ?

I think a better solution would be some type of recirculating filter assembly that could remove gas and moisture from the oil so it could go at least 10 hours between changes.

 

[Sidekick]

I wondered about the gas in crankcase for months...thinking it HAS to be loose rings/lousy valves. Very familiar with riding mowers with 'over full' dipsticks..... Gas tank is high, carb is low, gravity 'sucks' gas into carb,past 'anti dieselling solenoid', into cylinder, past rings, into crankcase/sump.
This Subaru engine though is fuel injected, seems everyone can smell LOTS of raw gas which is a huge 'red flag' that something is seriously wrong.

From what I was told it is caused when starting the engine below full operating temperature because it is a high compression engine and fuel blows by the rings until everything gets hot and expands. They call it short tripping and there is no fix. It is supposed to evaporate from the oil when hot. Never heard of anything like this before and wonder how the EPA allows fuel to evaporate into the air. Look at the garbage gas cans we have to prevent that. I think it is just something Kubota is trying to avoid that could open up a big bag of worms.

 

[GreensvilleJay]

hmm, so a terrible design of the engine ?
I can't see the gas 'evaporating into the air', and NOT change the nature of the engine oil.
maybe the OP should call the EPA about the problem.....

 

[Sidekick]

I feel your pain. I'll take it off your hands and give you CDN$5K for the machine as-is if you deliver it.

Waiting to see if the AG can help me get my $18k US back first .

 

[Sidekick]

hmm, so a terrible design of the engine ?
I can't see the gas 'evaporating into the air', and NOT change the nature of the engine oil.
maybe the OP should call the EPA about the problem.....

That is what the dealer was told by Kubota and put on the invoice as the problem. No way to contact the Kubota reps to verify anything as my email about this to my Kubota warranty contact was never answered. For some reason Kubota seems to be distancing themselves from exactly what the term SHORT TRIPPING that has been stated as the problem. Wish someone at Kubota cared and would explain this issue as it seems to affect others also.

 

[Siesta Sundance]

From what I was told it is caused when starting the engine below full operating temperature because it is a high compression engine and fuel blows by the rings until everything gets hot and expands. They call it short tripping and there is no fix. It is supposed to evaporate from the oil when hot. Never heard of anything like this before and wonder how the EPA allows fuel to evaporate into the air. Look at the garbage gas cans we have to prevent that. I think it is just something Kubota is trying to avoid that could open up a big bag of worms.

Consider changing out the oil to a thicker weight oil.

 

[D2Cat]

Consider changing out the oil to a thicker weight oil.

That might be the answer. Just run straight STP, if they even still sell it.

 

[GreensvilleJay]

so dealer here in Ontario has one for sale, I ask if gasser, yes, ask about 'engine problems', says' that's been fixed' ! So I've asked for whatever 'paperwork' he can send me about it....... don't hold your breath BUT maybe there IS a 'fix'.

 

[GreensvilleJay]

just got this.....

Who is your servicing dealer? It'll be bulletin TIB-2021-023/AG077-21

hopefully someone can find it,see what it says ....

 

[catalyst]

hmm, so a terrible design of the engine ?
I can't see the gas 'evaporating into the air', and NOT change the nature of the engine oil.
maybe the OP should call the EPA about the problem.....

I dont know enough about it to get the EPA involved. lol.

My understanding is that the "fix" is not a different model engine.

 

[Sidekick]

so dealer here in Ontario has one for sale, I ask if gasser, yes, ask about 'engine problems', says' that's been fixed' ! So I've asked for whatever 'paperwork' he can send me about it....... don't hold your breath BUT maybe there IS a 'fix'.

If he has a fix, please ask him to post it here. Kubota didn't have a solution other then blame it on me for short tripping.

just got this.....

Who is your servicing dealer? It'll be bulletin TIB-2021-023/AG077-21

hopefully someone can find it,see what it says ....

I can't find that in a search, I am praying they finally have a fix and hopefully will recognize it as a problem for others that have been affected. Only recall on mine was the washers put under the steering column last spring. My dealer is Blazey, his info is on the oil report.

 

[#40Fan]

@Sidekick Is there anything in the manual stating how the engine is supposed to be broke in?

It sounds like you and others have glazed cylinders from improper break-in periods which will cause low compression, blow-by, poor running and oil contamination. Might be able to fix it by honing the cylinders, replacing the rings and giving it a proper break-in.

Putting around at slow speed, low loads is bad for a new engine. Take catalyst's eninge hours/mile for example. 1000 miles in 400 hours is 2.5 mph average. I'm surprised it made it to 400 hours.

Good luck, guys. Start looking for electric golf carts. Sounds like they'd be exactly what you need.

 

[Sidekick]

@Sidekick Is there anything in the manual stating how the engine is supposed to be broke in?

It sounds like you and others have glazed cylinders from improper break-in periods which will cause low compression, blow-by, poor running and oil contamination. Might be able to fix it by honing the cylinders, replacing the rings and giving it a proper break-in.

Putting around at slow speed, low loads is bad for a new engine. Take catalyst's eninge hours/mile for example. 1000 miles in 400 hours is 2.5 mph average. I'm surprised it made it to 400 hours.

Good luck, guys. Start looking for electric golf carts. Sounds like they'd be exactly what you need.

Actually compression was the first thing the dealer was told to check and that is fine. Only break in is no full speed for 50 hours, and go slow. I have kept it mostly below 15 mph in low gear My wife has a golf cart we use for short trips to the garden but it can't go in the trails and pull firewood out and doesn't have a place to put all the yard maintenance equipment. Doesn't get used everyday and basically is a replacement for my old 1998 Deere 4100 with a cart that has seen the same treatment for 1200 hours without one problem.