Alert ...this is a long post so skip my rambling and go to the list of steps I did if you want. I did a search of the forums and did not see a similar post.
I so appreciate the great knowledge base here on this forum. I have many times looked and found the answer I needed. I hope this thread helps some newbies with a fuel flow issue.
My fairly new BX23s (2021 109 hrs.) starting acting up a few months ago. Would run fine at first but stutter and nearly die about 30 minutes after running. It was due for a filter change so I got on it. Seemed to fix it...alas this problem was intermittent and it returned within an hour of running. I should have come here sooner but.. I figured the fuel pump was the problem and replaced it. Nope, still ran rough. Bad fuel...that wouldn't be intermittent I thought but I drained and replaced it. anyway. Problem solved? Nope.
I called a Kubota mechanic who was great. He wanted to help but was at least 6 weeks out in scheduling. Despite being that busy he spent 30 minutes on the phone brainstorming the issue. Bottom line...fuel flow problem. He suggested blowing out the fuel lines. I probably had the fuel lines disconnected 3-4 times now and wasn't looking forward to another diesel bath so I decided to just try the return line. Ran for 20 min and same problem.
Yesterday I tried to blow out the line from the first filter to the tank. I first removed all the fuel. Then I removed the fuel filter and applied the air pressure. With the fuel out I was not surprised that no fuel flowed before I applied the air. After I used the air at least a pint flowed into the container. Finally a firm diagnosis! Gunk in the tank.
An accurate diagnosis is the key to an effective treatment plan, I used to tell medical students. Much to my dismay the suggested way to clean the tank of gunk seemed to involve dissembling the tractor to stage approximating its build about 3 hrs. after it's birth. There has to be better way.
Here is what I did:
I so appreciate the great knowledge base here on this forum. I have many times looked and found the answer I needed. I hope this thread helps some newbies with a fuel flow issue.
My fairly new BX23s (2021 109 hrs.) starting acting up a few months ago. Would run fine at first but stutter and nearly die about 30 minutes after running. It was due for a filter change so I got on it. Seemed to fix it...alas this problem was intermittent and it returned within an hour of running. I should have come here sooner but.. I figured the fuel pump was the problem and replaced it. Nope, still ran rough. Bad fuel...that wouldn't be intermittent I thought but I drained and replaced it. anyway. Problem solved? Nope.
I called a Kubota mechanic who was great. He wanted to help but was at least 6 weeks out in scheduling. Despite being that busy he spent 30 minutes on the phone brainstorming the issue. Bottom line...fuel flow problem. He suggested blowing out the fuel lines. I probably had the fuel lines disconnected 3-4 times now and wasn't looking forward to another diesel bath so I decided to just try the return line. Ran for 20 min and same problem.
Yesterday I tried to blow out the line from the first filter to the tank. I first removed all the fuel. Then I removed the fuel filter and applied the air pressure. With the fuel out I was not surprised that no fuel flowed before I applied the air. After I used the air at least a pint flowed into the container. Finally a firm diagnosis! Gunk in the tank.
An accurate diagnosis is the key to an effective treatment plan, I used to tell medical students. Much to my dismay the suggested way to clean the tank of gunk seemed to involve dissembling the tractor to stage approximating its build about 3 hrs. after it's birth. There has to be better way.
Here is what I did:
- With the fuel out I left the rear (first) filter off and the fuel hose dangling over a catch basin
- I sent 1-2 quarts of water via the garden hose into the fuel tank under high pressure. I collected that for the recycling center.
- Then over in the grass (where I was working) I removed the catch basin and rinsed out the tank vigorously with the hose in 4-5 cycles of rinse and drain. I did not use detergent though that may have been useful. I shoved that hose nozzle in there and turned it all around. As it was washing I shook the tractor by the ROPS. You can actually agitate a small tractor fairly well.
- I placed the cap loosely on the tank and left it overnight to drain and dry.
- In the am I used my shop vac to blow air into the tank for about 30 minutes and then reversed it to suck out any debris. I thought about dropping a magnet on a string into the tank but decided it was unnecessary. Actually I couldn't find a magnet that would work. That is probably worth doing if you suspect you dropped a metallic object in. I also thought about using a blow dryer to further dry it out. But decided not to do that.
- Because water is heavier than fuel, I reasoned that the first few ounces of new fuel I put into the tank would come out with water in it. I was surprised to fine that of the 16 oz or so of fuel I put in only a tablespoon or less showed a water fuel meniscus in the glass jar I used. I decanted the fuel into my portable diesel tank and sent the rest with the water into the catch basin.
- Satisfied that the tank was clean (at least cleaner) I put a new fuel filter on and started it up.
- Today I moved 30 yards of topsoil over 5 hours without a problem.
- The issue I dealt with is the classic fuel flow vs fuel quality. The easiest way to judge fuel flow is at the high pressure pump bleed screw. Cracking that open while the fuel pump is running should produce a torrent of flow. I failed to recognize the low flow I had when I started. If you have good flow then there is so no problem in the lines. Low flow means a blockage. But where.....the most likely place is going to be the unfiltered line from the tank to the first filter.
- Of course filters if not changed can be the culprit. I will not buy the metal canister filter in the future. Clear is the way to go.
- While it may not be as clean as if I removed the tank why remove half of the tractor and spend 4-8 hours to get to the tank simply to clean it? Made no sense to me. Time will tell!
