Five Minutes to Warm up a Tractor???

[SteveHGraham]

Today I finally got my big (relatively) Kubota going. I practically had to go back to college to figure out how to start it. Anyway, it's functional. I had to move it out of my shop because I am hosting a couple of families on hurricane night, and I wanted to open up space for their cars. I figure a tractor will not be bothered much by a little wind.

Here's a question: do I really have to let the tractor warm up for five minutes every time I use it? The manual appears to say I do. That's pretty crazy.

The bit about warming it up is next to some pages about cold weather, but I don't see any indication that the warm-up only applies to cold days.

[spro]

Hi Steve G. I wish you and yours safety during Irma and Jose. The five minutes is for cold weather as the gearboxes and pumps could be too cold to operate otherwise. The fluids are thick when very cold but the engine warms them up.

[SteveHGraham]

Thanks, spro. Irma's path has moved pretty far west, so I feel a lot better than I did yesterday.

[Russ Hanscom]

I have owned several Kubotas, never remember seeing the warm-up requirement. I am pretty sure it would only apply to very cold weather and then I am still not sure how that would work - you need to get the bits moving and fluid circulating for a warm-up to be effective.

[larry_g]

You can get a bit of an indication from the color of the exhaust and the 'smoothness' of the idle. Cold thick fuel does not atomize well so a bit of a warm up is advised. If you have been running the tractor then a warm up is not necessary.

lg
no neat sig line

[NP317]

Steve:
Hope the storm is not too bad on you. Good you are hosting others in need.
Take Care.
~RN

[warmstrong1955]

The 5 minute thing is just 'good practice', and really depends on the temp, not a big deal in Florida, and how long it's been sitting.
A little warm up time, gets all the oil moving & parts & bearings coated and where the oil needs to be.

Bill

[BadDog]

When I grew up in agricultural land, I was taught (and observed) never cranking a diesel and putting it right to work. Forged piston expansion to appropriate fit and other such temperature induced fits were cited, and I guess I still do it. I crank my Duramax and pull out of the garage basically at idle, then let it idle a bit before taking off. After a hard pull, leave it idling for a while to cool the turbo and prevent damage (mainly cooking oil that no longer flows). On the Kubota, I let it run for a few minutes before getting things under way. Not nearly as onerous as those blasted slow glow plugs. Holding the key in heat for 30 seconds is way more frustrating. In AZ temps it really shouldn't need a full heat, but cold compression is no longer quite what it should be, so I have to run a 30 second heat if I want to get it to crank without risking overheating the starter, or running the (becoming iffy) battery down so that it no longer spins fast enough.

[SteveHGraham]

Thanks for all the advice and the hurricane wishes. It looks like Irma bypassed everything my dad and I have in Dade County, and now it is likely to be gentle on Ocala.

I didn't run the big tractor (as contrasted with the little tractor) until yesterday. I really like it. I do not understand the transmission yet. Instead of gears, it has L-H-M-N. You set the throttle up by the steering wheel, which is what I expected, but there is a foot pedal that switches between forward and reverse.

I ran the bush hog a little bit today. I have to leave the tractor outside during the storm, so I moved it to the big pasture. On the way I tried to see how the bush hog cuts. It is not impressive. I assume I'm running it too slow and/or the blade is too high.

I think the blade is adjusted with a pin at the rear of the bush hog. I don't see a way to do it with hydraulics. Is that right?

Not sure how many RPM's to give the tractor when running the bush hog, or at any other time, for that matter. The little tractor is supposed to be run flat-out.

I finally have a good excuse to own a big diesel pickup. Fallen branches are a problem here due to lighting, so today I filled the bed with branches from the yard and drove them out to the burn pile. All I need now is a Marlboro cigarette.

[stephenc]

Most pto driven equipment is meant to be driven at 540 rpm , if you look at the tachometer there should be a little pto icon with 540 beside it .

If not your owners manual will say what engine rpm will give you 540 rpm

I doubt you'll run across any equipment that runs it , but sometimes you'll see stuff that needs 1000 rpm pto , they have a differant spline on the pto shaft though .

Most power take off systems are geared inside the tractor to match the peak of your engines horsepower / torque curve

Brush hogs , mowers and such aren't what you would call a rpm specific , once you get used to how things sound when running you just use it where everything sounds and feels comfortable

Oh and I almost forgot , you should look in your owners manual and see if you have a multi-speed pto , as in there is a high and low range for your pto .
If so check to be sure your in the right speed range .

[stephenc]

Some more thoughts on brush hogs .

When mowing rough areas where there is fear of hitting random objects a person's first thought might be to lower engine rpm's to help save on damage if you do hit something .

That is only a good idea to a point ... most modern tractors the pto is clutched , and on top of that a decent brush hog will have its own clutch in the drive line or at the least a shear pin .

At moderate to higher speeds if you hit an object you'll either break a shear pin or a clutch will slip .
But at lower speeds you run a risk of doing very bad things to the tractor or mower's gearbox , pto shaft ... or even your engines crankshaft because if you hit something there might not be enough power going to the pto to make the clutch slip or break a shear pin .

[BadDog]

The FNR rocker pedal and other trans descriptions describe the premium hydrostatic transmission (for most people). Much easier to operate in general, particularly with loader work. But the down side is complexity and buck loads of dollars when/if something goes wrong. I personally prefer a gear transmission just for brute strength and relative simplicity, plus it's what I grew up around, and you almost never hear of problems with them unless someone is getting really silly with it.

Hitting something with most small property hogs I've seen shouldn't be a problem. From what I recall they have a heavy sort of flywheel disk in the center that is domed a bit that helps it bump over stumps and rocks. The blades are really more like sharpened flails that mount to the rim of that wheel, and angular momentum throws them out as it runs. When you hit something, the inertia in the central hub helps absorb the energy, and the blades fold back to further reduce the shock, but can sound like a trip hammer when running. And finally, the shear pin (always carry a spare). I haven't seen a torque limiter (clutch) on small hogs, but I've only fooled with a few, and that was 30+ years ago. On old tractors, the PTO was direct driven, and could push the tractor forward until you bleed off the inertia. 2 stage clutches and over-drive sprags make that a non issue in most modern branded tractors, no idea about chinese.