Oil is the life-blood of your engine, and the more attention you pay it, the better off your engine will be.
The proper filling of oil on our walk-behind tractor engines is as follows:
CURRENTLY USED GAS ENGINES (Honda, Yamaha, Subaru-Robin): WITH ENGINE LEVEL, FILL TO OVERFLOWING. Regardless of what the owners’ manual may show, your Gas engine on your tractor does not have a “dipstick” on the oil fill cap… Why? Because we cut it off. Why did we do that? Because we like to save our customers money and trouble: The dipstick on all the engines we use (Honda, Yamaha, Subaru) is only an inch or so long, and is designed to show the minimum “safe” amount of oil in the engine with the engine operating in a level plane. The thing is, we know human nature, which is that if the person sees oil at the bottom of the dipstick, they think “Oh, it’s OK…I don’t need to go to the shed and get the oil bottle…it’s on the dipstick, so it’s SAFE, right?” But this equipment often operates at angles much too steep for that “minimum” amount of oil (mowing on a hillside, tilling to maximum depth, etc.)..and you only need to do that for a few minutes with too little oil in it, and the engine seizes up. WHOOPS. We learned a long time ago that if the oil is kept to the MAXIMUM allowable level in the engine, there is simply no chance of a low-oil failure. Therefore, we don’t give our customers a choice; we cut off the dipstick and ask that you keep it full to the overflowing point. (If the engine is level, you can’t “overfill” these gas engines, it’ll just run back out the fill hole if it’s too much.) Don’t take any chances! But make sure the engine is LEVEL before checking and filling, or you’re going to get a bad reading…this may require putting a block under the implement or something. (The above also applies to the older ACME engines that were used on BCS machines 20+ years ago.)
IF YOU HAVE A MACHINE WITH AN ENGINE TYPE NOT LISTED ABOVE (Such as: Briggs twin-cylinder Vanguard, Kohler Magnum, Briggs I/P, I/C or Intek), these engines may be equipped with a LONG (6 inches or more) oil dipstick, and this dipstick SHOULD be used as a guide for oil filling, with engine LEVEL.
KOHLER / LOMBARDINI DIESEL ENGINES: On these, it is almost the opposite: You DO NOT, absolutely DO NOT want to overfill a small diesel engine with oil!! Again, make sure the engine is LEVEL, and check the dipstick carefully. (yes, you DO want to use the dipstick on the Kohler/Lombardini diesel engines, it is the only way to check the oil level). It is hard to see the oil level on the stick when the oil is new, but you can see it if you’re persistent. Make sure the dipstick is fully pushed into the hole (they are TIGHT) before you pull it out to check, so you get a good reading. The oil level ONLY HAS TO BE ABOVE THE “LOW” MARK ON THE DIPSTICK TO BE “SAFE”, as the diesel engines have an oil pump that circulates the oil in the engine…so anywhere BETWEEN the lower and upper marks on the dipstick is OK, you do NOT have to try to hit the “upper” mark. OVERFILLING CAN CAUSE SEVERE ENGINE DAMAGE, AS THE ENGINE CAN START TO CONSUME ENGINE OIL AS IF IT WERE FUEL, AND THE ENGINE WILL OVERSPEED AND NOT SHUT OFF OR RESPOND TO THE THROTTLE CONTROL! (The ONLY way to shut an overspeeding diesel off is to jam something in the AIR INTAKE (like your shirt or a plastic bag or something), to smother off the air going into the engine….this will choke it out.)
The diesels hold between 1.25 and 1.5 quarts of oil (depending on engine model). When changing oil, after putting in one quart, CHECK THE DIPSTICK CAREFULLY!!
YANMAR diesel engines have the oil fill and dipstick in the same cap. These engines can be filled to overflowing with engine level, just like the gas engines above.
Lombardini/ Kohler diesels are equipped with a CLEANABLE oil filter, see our General Diesel Instructions document for details.
All tractors are test-run by us prior to shipping, so they are properly filled with oil when you get your tractor. (EXCEPTION: if you live in a country outside the USA AND we have shipped your tractor by air-freight, there will be NO oil in the engine or transmission.)
Engine Oil should be changed after a running period of 5-8 hours for initial “break-in”. After that, change every 30-40 hours for Gas engines; 40-60 hours for diesel.
The engine owners’ manual supplied with your tractor gives manufacturers’ recommendations for oil type, but we can tell you from experience that a good quality 15W40 engine (such as Shell Rotella or equivalent) will work in virtually any engine, Gas or Diesel, and in most any weather conditions. We use an oil of this type for our “shop” engine oil, which we have in 55 gallon drums. However, in very cold temperatures (below 15 degrees F), a lighter weight oil may be required for easier starting, such as a 10W30 or 5W30. This light an oil should be drained out, however, when you get back into the warm season…the heavier weight oil gives much better high-temperature protection for an air-cooled engine.
Some folks may want to use a straight 30W oil, and that is fine, but you will find it takes more effort to start the engine in cooler weather. If straight 30W or 40W is used, make sure it is a detergent-type oil…NOT a “Non-detergent” oil!
Also, for anyone who wants to use it: all these engines are perfectly compatible with synthetic and synthetic blend oils. Our recommendation is that the engine should be run on “conventional” oil the initial 5-8 hours for break-in, then another oil change (30-60 hours, depending on engine) on conventional, THEN put synthetic in. This assures full break-in before switching to a synthetic. Synthetic oils are pretty much proven to reduce wear through increased heat resistance and less oil breakdown, and I run Schaeffer brand 15W40 synthetic blend oil in my own machine year-round.
(For transmission and implement oil recommendations, see the Tractor and Implements tabs.)
All modern diesel manufacturers recommend the use of “ultra-low sulfur” diesel fuel. Regarding BioDiesel: Technically, engine warranties are void if Biodiesel levels of greater than 5% are used in them, but frankly we have seen NO problems with folks running up to B100 in these engines, other than some accelerated rubber-fuel-line deterioration…which can be circumvented by replacing the lines with Viton tubing (or any other acid-resistant tubing) when they do go bad. These acid-resistant tubing can be gotten at most auto-parts stores, on the internet from various suppliers, and we also stock it here at Earth Tools. Diesel fuel is very stable, and can be stored up to a year (possibly more) if kept in sealed containers, out of the sunlight.
SPECIAL NOTE: On all Honda engines with Hi-rise fuel caps (where cap is approximately 1” tall, chrome steel), Honda recommeds filling fuel tanks NO MORE THAN ¾ FULL. Filling over ¾ full may cause the cap venting element to “seal” itself, resulting in “vacuum-locking” the tank after the engine has run 20-30 minutes.
(Recommendations by Joel Dufour, Earth Tools owner, sharing 30+ years of experience with small engines)
Modern small 4-cycle gasoline engines do not technically require higher than a 87 octane fuel, but based on experience, I would typically recommend a higher octane; at least 89, for a bit better high-temperature protection for the engine. The more important thing to look for in fuel these days is a lower “additive” content…but that is virtually impossible to find. Between alcohols, cutting agents, and 4 different types of ether that are typically added to gasoline these days, you are almost bound to have fuel system problems eventually if you don’t take the necessary precautions.
The biggest problem with all these additives is that they either : A. Attract water (alcohols); or B. evaporate quickly (other additives I mentioned), taking the “lighter-end” agents of the gasoline with them and resulting in a varnishy, stale, unburnable fuel in a relatively short time. I recently read a chemical analysis of modern gasoline that stated that unleaded regular unleaded is now around 50% chemically “Gasoline” by volume. So the other 50% are made up of the stuff I mentioned above…a substance called Toluene is actually about 25% of the volume. (We still call what we buy at the pump “Gasoline”, but it has become a generic term, kind of like “Kleenex” to describe facial tissue.)
Many small-engine manufacturers are learning to cope with this, simply by recommending that gasoline be not kept around for long periods of time (for example, STIHL chain saw owners manuals recommend that fuel kept longer than 30 DAYS be disposed of…this is a bit excessive, but they are just covering their tails).
My recommendations for gasoline storage & engine prep for storage:
Gasoline in storage containers should be kept SEALED and out of direct sunlight to maximize storage life.
Never keep gasoline in storage containers longer than 90 days. If the gas you have on hand in containers exceeds this age, pour it in your vehicle (not if the vehicle is a diesel, of course!)…your vehicle engine is MUCH less sensitive to fuel quality than your small engine. (however, if stored gasoline is much over 6 months old, I would hesitate to even pour it in a vehicle…)
If your small engine has a METAL fuel tank, storage of the engine (for more than 30 days) should occur with the tank FULL (or, as full as recommended…see note at top) in order to keep the inside of the tank from rusting in moist environments. In this case, you will want to first turn the fuel shut-off valve OFF, then start the engine and let it burn all the fuel out of the carburetor. So, the engine is stored with a “full” tank of fuel, but an empty carb. For storage periods longer than 60 days, it is not a bad idea to first put some fuel stabilizer in the tank, then run the engine for a few minutes to make sure the “stabilized” fuel in in the carb, THEN shut off the fuel and let the engine burn the fuel out of the carb. This way, whatever drops of fuel are left in the carb are ‘stabilized’ fuel, and while in my experience, ‘stabilized’ fuel can still go stale (meaning it will not burn well), it at least doesn’t coagulate to a varnishy gook and plug up the carburetor.
If you have a PLASTIC fuel tank on the engine, for over 60-day storage, you can simply drain the fuel out of the tank and run the carb dry. Plastic fuel tanks cannot rust.
Now, all this said: I will share a bit more personal experience on gasoline with you: I personally NEVER drain fuel out of any of my small engines, I never add stabilizer, and I never burn the fuel out of carburetors, even if I am going to leave an engine idle for 6 months or more. I also haven’t had to repair any carburetor or fuel system on anything I own in the last 20 years. WHY? Because I go to the slightly more trouble and expense of buying Aviation grade, 100 octane gasoline for use in all my small engines. This is, simply put, the highest quality gasoline available on the market today. It has virtually no additives, has a low evaporation rate/low vapor pressure, boils at a much higher temperature (resulting in NO vapor locks, no matter how old the engine is you’re running it in), and has a “shelf life” of OVER 2 YEARS in a sealed fuel container. There’s a reason they use that stuff in light planes: People’s lives depend on the fuel quality. (If your light plane vapor-locks at 8,000 feet, what are you gonna do, pull over and let it cool off?) While regular unleaded fuel is around 50% “gasoline” by chemical analysis, 100LL AvGas is 90 to 95% “gasoline”.
The extra octane this fuel has is not necessary for these small engines, but it can’t hurt them. Anyone who claims that high-octane fuel can damage an engine needs to go back to high school and learn about octane: is is a measurement of how hot a fuel can get before it spontaneously combusts. This is why if you have a race-car engine, you go out of your way to buy high-octane fuel for the thing…a high-compression engine with more lead timing RUNS HOTTER, and if you put a low-octane fuel in it, you will kiss your investment in a hot-rodded engine goodbye, as it blows holes in the pistons from preignition and detonation. In a “low-performance” engine, like one of these small engines, extra octane in not NEEDED, but it cannot HURT the engine.
I don’t use the Aviation grade fuel for the octane, that’s just a side-effect. I use it for the inherent stability of the fuel. (BTW: 100 octane low-lead Aviation gasoline [100LL] is PERFECTLY LEGAL to use in any OFF-ROAD application…it is just not legal to run in your vehicle, because there is no “road tax” applied to the purchase price.)
Now, the 100LL fuel IS leaded fuel…this is the one down-side, as no one can argue against the fact that lead is toxic. It has half the amount of lead as leaded fuel did pre-lead-phaseout (2 grams per gallon in 100LL, vs. 4 grams per gallon in leaded regular in say, 1974). You personally will have to balance the pros & cons of using a leaded fuel vs. having potential fuel system reliability issues from using the “standard” gas from a filling station. For example, if you have an organic market farm, leaded fuel may be a bad idea…you don’t really want high concentrations of heavy metals accumulating in your soil over time. But, if you are a home gardener who uses your equipment less often, the up-sides of not having to bring your lawn & garden equipment to the service shop for fuel system repairs (which takes time & money…not to mention burning more fuel to get back & forth to the shop!) may outweigh the small amount of lead emitted in the relatively few gallons of fuel you will burn as a part-time user.
There is apparently a movement to take the lead OUT of aviation-grade gasoline, which I think would be great…it would be nice to have the advantages of a very pure, high-quality gasoline, without the byproduct of emitting lead. But this has not happened yet, to my knowledge…
So, there it all is…choose whatever fuel works best for you.
PDF: Tractor Lubrication
Slow Internet? TEXT INSTRUCTIONS for QUICK-COUPLINGS use & maintenance
Most PTO-driven implements for walk-behind tractors have a gearbox for the rotating shafts/gears. The “rule of thumb” on implement gearboxes is to keep the oil level at ½ full. There are usually no dip-sticks on implements, but half-full can be determined by simply looking at the gearbox and judging roughly half the height…this will typically result in the gear oil level being about 2 inches below the top of the filler port. You can also stick a wire or thin screwdriver in to gauge the level. EXCEPTION: The Berta Rotary Plows have an oil fill/check port on the SIDE of their gearbox, oriented at the halfway point. So all you have to do is remove the plug with the plow sitting level on its plow rotor (OFF the tractor, so the top cover of the plow is parallel to the ground), and if oil oozes out, the oil level is correct. If none comes out, put oil in until it wants to come back out the hole.
TIPS ON CHECKING OIL LEVELS IN TILLER IMPLEMENTS: On the BCS brand tillers manufactured after 1987, the top cover of the tiller needs to be raised in order to get to the oil plug on top of the gearbox. To do this, remove the two nuts & bolts in the back, under the cover (one links the cover brace to the gearbox, the other links the depth-bar together…you need 2 – 13mm wrenches) and then use the large front bolt & nut as a “hinge”, and flip the cover up so you can check the oil. On Grillo brand tillers, the oil plug is on the right side of the gearbox…there are 5 bolts around the “edge” of the gearbox cover that hold the cover onto the gearbox body, and then there is this “extra” bolt that is more toward the middle/rear, at the “halfway up” point. THAT one is the oil plug. With the tiller attached to the tractor, take the plug out and if oil oozes out, the level is correct. If no oil comes out, it is low and needs to be added. This is such a small hole, getting oil in can be a real bugger. We find that using a turkey baster with a thin needle works great; just stick it down in the hole and squeeze oil in a little at a time until it oozes back out.
The type of oil used in most implement gearboxes is SAE 90w, 80w90 or 85w140 gear oil or any similar-weight gear oil. Implements are not typically choosy about oil weight…it is more important that there is oil in it!! EXCEPTION: The R2 Rinaldi brand Power Harrows recommend an EP, NLGI “0” Grease (in mechanic or electrician lingo, “One Ot” Grease) …this is a very light-weight grease, which liquefies (when at operating temperature) to a thick gear oil. (EP stands for Extreme Pressure). The power harrows do not need to be half-full…one-third full is fine. Also, if it is below 75 degrees, it is best to run the harrow a few minutes before checking the oil to warm it up, as in cooler temps the lubricant is too thick to “flow” well and may not give a good reading.
Oil level in implements should be checked AT LEAST once per year, and MORE in implements where the output shaft is exposed to lots of material that could wrap around the shaft and damage the oil seals (such as a Brush Mower). Gear oil in implements does not need to be changed much, since implement gearboxes are typically “sealed” (non-vented), and therefore moisture cannot get in. Still, it is a good idea to change gear oil every two or three years….UNLESS you switch to Synthetic gear oil, in which case you can leave the stuff in there 10 years or more, as synthetic gear oil has amazing lifespan characteristics. (Most synthetic gear oil is something like 75w90 or 75w140, and these are fine.)
Only a few implements have grease fittings on them; these are lubricated with multi-purpose grease in a standard zerk-type grease gun. These implements are:
- Lawn mowers: On front caster wheels; grease every 30 hours of use
- Haybalers: (various locations); grease every 50 hours of use
- Hayrakes: (various locations); grease every 50 hours of use
- Cutter bar mowers:
- Oil bath type: on “float” joint near where mower attaches to tractor; grease once per year.
- Newer Double-action cutter bars: same as above, plus on blade drive pins; grease every 20 hours of use.
- Grease-gearbox type: grease all 3 fittings every 4 - 6 hours of use
- Power Harrow: On PTO mount “swivel”, mesh-roller axle and screw-crank for height adjustment; grease every 20 hours of use
- Flail Mowers: Each end of mower blade shaft, and, depending on brand, also possibly on the end of “transfer” shaft (right of input gearbox): Grease every 40 hours of use (JUST 2 PUMPS). On Berta brand flail mowers, if equipped with a quick-coupling to attach to the tractor, also keep the male quick-coupling greased as needed (so it does not get “dry”)—you just have to smear some grease on, there is not fitting here. ALSO: if your flail mower is equipped with front “caster” wheels, there are probably grease fittings on those. Grease every 40 hours of use.
- Brush Mowers: On “swivel” joint that allows mower to “float” with ground contours; grease every 20 hours of use.
- Crimper/Roller: Axle shaft; grease once per year; just a couple pumps on each bearing.
- Rescia Guiliano brand Snowblowers: Chain-drive enclosure; grease every 20 hours of use (10 pumps max).
If you have an implement NOT listed here, and you see a grease fitting on it…by all means, grease it!! We are not infallible …