Cold Weather Starting Tips

The arrival of winter. Subzero temperatures across Canada and the United States. Time for a refresher course on how to get your Kubota tractor starting in cold weather. We will assume that you are already using the appropriate cold weather diesel (or the correct additives) to prevent your fuel from gelling.

There are a few things as a Kubota owner that you can do to help yourself when it comes time to start your tractor up in cold weather. They are:

  • park your Kubota in a shed or garage
  • install and use an engine block heater
  • use a fully charged battery

Parking your Kubota
Simply by parking your tractor inside a shed or garage you help keep the wind and cold away from the engine. It is also a lot more comfortable to work in a garage when it comes time to get your tractor to turn over. If you do not have access to a shed or garage, even a treed area that cuts the wind a bit is better than leaving your equipment in the open.

Engine Block Heater
Some Kubotas come equipped with a block heater from the factory, others, like the L175, L185, L1500, L1501, L2000 and so on, do not come equipped with these. The reason being is that the water jacket on these models is too shallow to accomodoate a block heater. Admittedly, it was a manufacturing oversight on Kubota’s part. In either case, it is possible to purchase a magnetic block heater from a local auto parts supplier and attach it to the bottom of the oil pan. It will heat the oil and the warm oil will warm the block and water jacket. Having warm oil also means the engine and starter do not have to fight against thick cold oil during cranking. The magnetic heaters that we use are 1500 watts, substantially more than the 75 watt factory-equipped heaters. Figure on paying around $30-40 for one of these aftermarket heaters.

Charged Battery
A battery’s ability to provide full cranking power degrades as the temperature drops. If your battery was not 100% charged or is in poor condition to begin with, the cold will only make that problem more apparent.

Glow Plug Preheat
The glow plugs in your Kubota serve to preheat the combustion chamber so that the diesel fuel will ignite and kick off combustion. After the engine is turning the compression of the engine spontaneously causes the fuel to combust and the glow plugs are no longer heated – they are just used to start this process. To preheat the glow plugs we turn the ignition key counter-clockwise and hold it there for a period of time. In cold weather, we recommend at least 60 seconds of glow plug preheat. Most Kubotas are equipped with a preheat indicator that will light up when the glow plugs are heated.

After preheating the glow plugs for 60-90 seconds, fully depress the gas pedal and begin to crank the engine. If the engine fires but it running choppy or “lumpy”, it is okay to turn the key back to the preheat position to heat those plugs up again. If it is very cold and the battery has lost its effeciency and is having trouble turning the engine over, its a good idea to use the cylinder head decompression knob located on the dashboard (L1-18, L1-20, L1-22, L1-24, L1-26 series are not equipped with this option). This relieves the cylinder head of some of the compression, allowing the weakened battery to turn over the engine a little easier because it has less compression to contend with.

A Word on Ether
Many years ago it may have been common practice to introduce ether into the airbox during cold weather cranking to kick off combustion. This is no longer the case for your Kubota engine. Introducing ether in this manner will seriously damage your engine and shorten its working lifespan. The combustion that results from burning ether is so volatile that a high compression diesel engine will freely race uncontrollably until that fuel is spent – turning the key to the off position or no longer heating the glow plugs will not stop that reaction. Diesel fuel is an oil and lubricates the inside of your engine – a property that an alcohol like ether does not have. Just do not use ether to start your Kubota in cold weather period.

Let it Idle
In cold weather, after your tractor has started, let it stand and run for a good 20 minutes. Adjust the idle up to around 1500-1700 RPM and just let it sit. The reason we do this is so that the heat of the engine dissapates into the transmission, transfer case and gear drives of the tractor. If we went to work right away, the gear oil is so thick that the hydraulics will not work and shifting gears is problematic. A common service task is to repair a shifter fork during a cold weather season – the gear oil is so cold and thick that when the operator grabs the stick to put the tractor into gear, the shifter fork breaks off inside the transmission – costly. Let the tractor warm up for a period of at least 20 minutes when in cold weather.

Taking a Break? Let it Run
Suppose that you’ve warmed up your Kubota, done some work and now want to shut it down to take a break and return 10-15 minutes later to start it up again. In this case, we recommend that you just let your Kubota idle. It will not overheat and at idle it uses very little fuel. Taking a break with the engine off, might mean that you have to let the tractor warm up again for that 20 minute period anyway.

Service Department Vic

Related Articles
Are you “gellin’”? A Tip for Cold Climate Kubotas
Trouble Starting your Kubota? Skip the Starting Fluid.
How to Use your Kubota’s Differential Lock
How to Install Tire Chains on your Kubota


  1. sheepguy Said,

    December 28, 2008 @ 7:46 am

    Where do I find aftermarket 1500 watt magnetic heaters as described in the article?

  2. Vic Said,

    December 28, 2008 @ 1:04 pm

    The magnetic heater we have in the shop is actually a magnetic water tank heater we picked up from a feed dealer several years ago!

    We’ve used it many times as a way to quickly thaw a frozen engine. And I do mean quick!

    I’m not certain that the manufacturer actually intended the one we have to be used as a permanent engine block heater because of the higher than normal wattage and the fact that it has no hi-heat shut off.

    These devices are finding a new market as the heater of choice for anyone running bio diesel in their truck as the builder, Zerostart, also makes several circulating tank heaters that also chime out 1500 watts.

    I would recommend that if you will be leaving the heater on the engine block un-attended (over night or for a few days for example) then purchase the more common 200-300 watt magnetic heater versions as they provide steady consistent heat over an extended period of time.

    These versions are safer, have built in thermostatic controls so they never get too hot. You should be able to source at NAPA, Canadian Tire, Lordco, UAP or similar auto parts/diesel performance or Ag equipment dealer.

    Service Dept Vic

  3. Mary Beth Said,

    January 10, 2009 @ 6:05 pm

    I have a plug -in block heater I installed in my B7510…I always wonder how long I should keep it plugged in before cranking it up…it seems like it smoother when its plugged in for at least a few hours…is there a point where leaving it plugged in overnight is harmful to the engine? For example….if I know its going to be minus 10 overnight and I want to plow the next morning would it be ok to plug her in the night before?

  4. Vic Said,

    January 10, 2009 @ 7:34 pm

    Mary Beth, You can leave your Kubota plugged in for days if required. The element in the block heater is designed to crank out a specific amount of heat, and is “high limit” thermo protected.

    Overheating the tractor with the block heater would never happen as the heat generated from the block heater does not become an exponential.

    Plug it in for as long as you feel necessary being mindful of energy conservation. Overnight is completley acceptable!

    Service Dept Vic

  5. Ben Said,

    January 14, 2009 @ 8:21 am

    You should be able to leave it plugged in. When I was running a dairy farm, I used to keep the main tractor plugged in 24/7 in the winter because if we lost power I’d have to be able to start it immediatly to run the generator. Now that starting is less critical, I usually get up around 4:30 to plug in the block heater, then go back to bed until 6:00, 1-2 hours is generally enough to warm the engine. If it’s going below -30F, I’ll probably plug the heater in the evening (mostly so that I don’t have to go out in the morning until I’m ready)

  6. John Milito Said,

    March 3, 2009 @ 8:51 pm

    Hi Vic; I have an old B-20 and I don’t have a cylinder head decompression knob you mention on CRANKING, on my dash or anywhere else I can see. Do I have one? Would be helpful for cold weather starts in Canada. Thanks for your expert advice.

  7. Vic Said,

    March 4, 2009 @ 9:02 am

    John, There is no cyl head decomp on your B20. Are you having trouble starting it? Assuming you have a good strong battery with a MINIMUM of 850-1000 CCA try this start technique on that cold blooded Kubota! Don’t glow the plugs, but crank the tractor over for 15-20 seconds until it starts to blow white smoke. Stop cranking, and then glow the plugs for a full 45-60 seconds. This will feel like an eternity when you’re freezing your ass off, but it has to be done! After glowing for the appropriate time, crank the engine over, with the throttle or gas pedal held half way. When tractor fires it may start running a little lumpy, so, re-glow the plugs until the engine smooths out, (usually only a few seconds) then reduce throttle to high idle after running smooth. That’ll get ya goin’!!

    Service Dept Vic

  8. John Milito Said,

    March 23, 2009 @ 6:59 pm

    Hi Vic; Thanks for the tip. I figured out my battery didn’t have enough power. The cold weather killed it down, so my glow plugs didn’t heat up enough. The temperature that morning was -22 C. I had my block heater on but I missed the part you said about taking your battery in at night. I’m a Kubota newbie and loving the cold learning curve. Thanks! John

  9. Mike J Said,

    November 9, 2009 @ 8:14 pm

    By the laws of science a battery is at 50% efficiency at 32F (0C); that means your 800 CCA (Cold Cranking Amp) battery is down to 400 even before you start. A really effective and cheap aid is to buy a battery heating pad and put it under the battery. Sorta like that hot pad Granpaw put under his achin back :) Then just plug that heating pad for an hour before cranking and… wallah, full battery power.

  10. Rick Bromstad Said,

    November 13, 2009 @ 2:28 pm

    To help with transmission operation in winter I switched to an equal synthetic tranny fluid reccomended by my bulk oil dealer. I’ve used it for 20 years now and never had a minute of trouble,and what a difference in warmup time

  11. Bob F Said,

    November 17, 2009 @ 6:20 pm

    How well do the radiator hose heaters work. What the pros and cons as compared to the block heater. I hava a L245 DT

  12. Pete Said,

    January 24, 2010 @ 5:32 pm

    At what temp should you plug in the engine block heater before starting?

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