Kubota BX2670 Fuel Filter Freezing up in Cold Weather

landrand · Dec 26, 2022

A couple of years ago, I had an issue with the fuel filter on my Kubota BX2670 freezing up in cold weather. In below freezing weather, I'd start up the tractor and let it idle and after a couple of minutes the engine would sputter and stall out. I wouldn't be able to start the engine again as the frozen filter prevented fuel from getting to the fuel injection pump.

I replace the front fuel filter and that helped, but after a year I had the same problem. Rather than change out the filter again, I just used an electric hair dryer and warmed the fuel filter on the side of the engine. I could then start the engine, let it warm up, and didn't have a problem with the filter freezing up and cutting off fuel as the tractor engine heat kept the filter from freezing. I used this procedure all last winter here in Northern Michigan.

Yesterday, it was about 14 def F and I was getting ready to snow blow the driveway. As usual, I warmed up the front fuel filter with a hair dryer for about 8 minutes, started the tractor, and let it sit idling for about 15 minutes to warm up. I jumped on the tractor, and started to blow snow and everything seemed normal. After about another 8 minutes, the tractor engine started to sputter and bog down. With the throttle in the low position, the engine would run very rough but it would idle. If I increased the throttle, it would run rougher and almost stall out. The key is the engine was getting fuel as it would run, but it would run very rough.

I let the tractor sit for about an hour or two as I drove to town to get some kind of diesel fuel stabilizer/non-gelling additive (Howes) as I thought I'd give that a try. When I returned home, I added a little fuel stabilizer to the tank and did my normal procedure. I warmed the front fuel filter for about 5 minutes, started the tractor and let it idle for about 10 minutes. I then started to blow snow and after about 10 minutes, the tractor again started to sputter and bog down.

I understand I probably have moisture with my diesel fuel, but it seems wierd that it would run normal for about 8 to 10 minutes and then all of a sudden, the engine would sputter and bog down. It would idle very rough, but wouldn't stall out unless I increased the fuel throttle. Only if I let the tractor sit for a couple of hours would I be able to get it to temporarily run normal again.

Any ideas, recommendations? I am using winter grade diesel fuel that was bought in middle of November so it should be rated for this cold weather. Why Kubota doesn't put a fuel water separator on these tractors is beyond me. Thanks for the help!

dodge man · Dec 26, 2022

Unless things have changed there are two fuel filters, one underneath towards the back. Have you changed that. When I had my BX I had the little filters towards the back gel up twice. I added a Racor filter and it gelled up once. I have since started adding kerosene to my diesel along with an additive, no gelling since with the BX I had and my current JD. All three times my fuel gelled I was using Howes. I don’t think there anything wrong with that product, it just only does so much.

KWentling · Dec 26, 2022

I would check your fuel cap and make sure it is venting. You can do that by loosening the cap when it is running poorly and see if that helps. Fuel treatment is best done above 35F but winter fuel "shouldn't" need treatment, but I do it anyway. There are some here that have added a Raycor separator to their BX's. All my fuel goes through a water separator filter as it's pumped into the tractors so I haven't pursued that.

landrand · Dec 26, 2022

dodge man said:
Unless things have changed there are two fuel filters, one underneath towards the back. Have you changed that. When I had my BX I had the little filters towards the back gel up twice. I added a Racor filter and it gelled up once. I have since started adding kerosene to my diesel along with an additive, no gelling since with the BX I had and my current JD. All three times my fuel gelled I was using Howes. I don’t think there anything wrong with that product, it just only does so much.

I'm going to change the rear fuel filter today and give that a try. Thanks for the info.

landrand · Dec 26, 2022

KWentling said:
I would check your fuel cap and make sure it is venting. You can do that by loosening the cap when it is running poorly and see if that helps. Fuel treatment is best done above 35F but winter fuel "shouldn't" need treatment, but I do it anyway. There are some here that have added a Raycor separator to their BX's. All my fuel goes through a water separator filter as it's pumped into the tractors so I haven't pursued that.

I just did a search on the hard running in cold weather and saw a post about the fuel cap not venting properly. Yesterday, when putting the fuel additive in the tank, the bottome of the fuel cap did have some frozen crystals on the bottom. I hope that's the issue; cap not venting properly and causing issues with fuel suction etc.

I'll look into the Raycor separator. Something needs to be done to this BX as it's a pain in the ass to get this tractor started and running well when the temps are below freezing.

LouNY · Dec 26, 2022

Most likely your fuel is gelling and the paraffin is plugging the filters,
adding an anti gelling treatment to already gelled fuel doesnt work.
When the fuel gets warmed up most of the paraffin will go back into suspension.

seville009 · Dec 26, 2022

I put Diesel 911 in my diesel cans so it’s already in it when I fill the tractor. Helps alot with the gelling fuel.

dodge man · Dec 26, 2022

Diesel911 is not designed to be a regular additive, just used for emergencies when you’ve already gelled. It contains additives that are hard on the fuel system if used all the times. Power Service makes an antigel additive that is designed for winter use along with Howes, Standyne and several others.

Seven Gables · Dec 26, 2022

I started doing commercial snow removal in 1985 with a case 1494 tractor and rear mounted 8’ snowblower. Had the fuel filter wax up and stall the tractor in a bank parking lot I was blowing in cold windy storm like we just went through, had to put new filter on and bleed it right there in the lot to get it running. That taught me well so ever since I’ve religiously used the Power Service while jug anti gel at 1oz to every 3gals diesel. 4 different tractors and 37 years of snowblowing since I’ve never had a fuel gel/wax failure. I’m sold on it

landrand · Dec 27, 2022

Today I did the following with my Kubota as the temperature was about 14 deg F. I removed the gas cap and cleaned the ice around the "tubes/vents". It did look like it could have been clogged.

I used my hair dryer and warmed the front fuel filter for about 5 minutes. I started the tractor and let it idle and warm up for about 12 minutes. I then hopped on it and began blowing snow for about 10 minutes and then the engine suddenly bogged down and ran very rough. When running rough, I opened the gas cap and that didn't help so the gas cap venting was not causing the issue.

I turned off the engine, got a small electric space heater and put it under the rear fuel filter for about 20 minutes. Every 5 minutes I started up the tractor, and again the engine would run very rough. After about 20 minutes, I added a little 911 to the the gas tank and while the heater underneath was still on. I waited 5 more minutes and started the tractor. It started up and the engine appeared to run fine. I let it warm up for about 8 minutes and then started blowing snow. I blew snow for the next 4 hours and the tractor ran very well.

I don't know if it was applying heat to the rear fuel filter or the combination of applying heat and using the 911 in the fuel tank. In any case, I was happy to get my Kubota running again in this cold weather as I have to clear about 2 feet of snow in an area where I have 9 Scottish Highlands. I was getting nervous as my small cattle operation here in Northern Michigan depends on clearing snow so I can put out hay bales and clear a path to a small pond that I use to fill the cows water tanks.

If my filters are clogging up with parafin wax, will the 911 remove the wax or should I still change the fuel filters? My front fuel filter probably has less than 30 hours on it. I've been assuming my fuel filters were freezing up do to water, not wax.

Seven Gables · Dec 27, 2022

I would definitely replace both

NHBX · Dec 27, 2022

Another fan of power service white bottle.
I would also change both filters as Seven Gables suggested. In addition I would drain some fuel out of the bottom of the tank to see what it looks like. Moisture in the fuel will also cause the filters to ”freeze” and plug. Good luck I hope you get it straightened out.

RjCorazza · Dec 27, 2022

@landrand
Sounds like you are getting a handle on your BX fuel problem.
My contribution would be to use an antigel additive regardless of how the fuel is treated at the pump. The Power Service 911 is a great product for dealing with currently gelled fuel, but as mentioned it's not for routine fuel treatment. My preference is the Power Service white bottle at the same concentration mentioned by an earlier poster of 1oz per 3 gallons diesel. I made up a simple chart in excel that calculates the required dose in multiple measuring units.

Additionally, adding a water separator / filter will go a long way in preventing water problems. With a clear bowl and drain you will have a visual indication of water contamination, which can be simply drained off (then deal with the tank contamination). There are numerous YouTube videos specific to the BX machines that describe various solutions. There are also several ready made kits to relocate the BX filter.
I replaced my small separator / strainer with a Racor water separator / filter. They can even be ordered with 12v fuel heaters for use in very cold climates for additional insurance, but my area is not really very cold so I skipped the heater.

Egon · Dec 27, 2022

Have you checked your fuel storage tank for gelling And water?You might also cover the tractor with a tarp and place a 1500 watt or so heater underneath. That should heat every thing including the fuel tank. Then drain out the fuel/water and replace with treated winter fuel. Your fuel supply may have been purchased before the switch over to diesel fuel At the station.

Note: fuel additive that contains alcohol is not good for the injection pump.

nyone · Dec 28, 2022

LouNY said:
adding an anti gelling treatment to already gelled fuel doesnt work

This!
Its basicly like pouring jelly on peanut butter and expecting it to mix. By the time you know your fuel is gelled it's to late to add something to the tank. The best practice is to be mixing antigell into your fuel when the temps drop below 32*f.

Your option now is to get heat on the fuel tank and lines.

You also know why every tractor owner that uses there machine to clear snow should have 2+ fuel filters in stock.

i7win7 · Dec 28, 2022

The BX's have a fuel filter in front of the hydro cooling fan. Had same problem as landrand with mower deck locked into TOP position. Real hard to get heat gun on filter. Bought 6' of fuel line, clamps and a splice to mover lower filter in front of FEL mount

and use power service on a 50gal tank

crashz · Dec 28, 2022

My first year with the Kubota we got a cold spell and I had forgotten about the summer fuel in the tank. I went to plow the snow and had a heck of a time.

I learned this:
- I simply could not get enough heat to the lines and filter to liquify the wax/ice. It was below zero at the time, but even with a big salamander heater, I couldn't get it.
- Batteries quickly die in that cold too.
- A small amount of kerosene works better than 911. I could actually see the wax disappear in the filter housing.
- Treating the fuel AFTER it jelled was pointless.

Now I keep a gallon of kerosene on hand and treat the fuel year round.

arto98607 · Dec 29, 2022

I am sure kerosene works, but I would not be adding it year round to my Diesel fuel.

Something like this may be safer alternative, and there are many other choices:

dodge man · Dec 29, 2022

I added this Racor to mine as shown and eliminated the one near the back of the tractor. This one still gelled on me but at least it was easy to change and you could clearly see the problem. One thing that I always thought is the fuel filters, no matter the setup are hanging out in the cold air where the fuel tank is a larger volume and would take longer to get cold.