Starting Kubota

[MChalkley]

I don't think tapping the throttle on a diesel before it's started does anything, actually. There's no pressure in the injector lines, so there's no way any fuel could be forced through the injectors into the engine. And if it did, it wouldn't atomize due to the insufficient pressure - it would just dribble onto the top of the piston or into the precombustion chamber, in the case of indirect injection, and waste a little fuel.

Jesse's original question, however, on whether it should be tapped while cranking is a different issue. Some older diesel engines recommended this because the injection pump always delivered only enough fuel at idle to keep the engine idling, which was often not enough to start a cold engine. So they had you open the throttle somewhat or tap the accelerator. Most modern injection pumps are smart enough to know whether the engine is running or not and compensate via the governor mechanism or a similar approach, unless it's a computer controlled injection pump, in which case it's all handled by the computer, of course.

So I don't tap, and rarely open the throttle, unless it's very cold outside. As for the glow plug, if the light is on, I wait for it to go out before starting the engine.

Mark

 

[gordon]

Re: Starting Kubota...Gordon

You know how you don't even realize that your doing something until someone points it out to you and when they ask why your reply might be---just kuz---.

I thought about the reason behind tapping the pedal before starting and it then became pretty clear why.
The reason being on my 2350 I have a shutoff lever that I pull up to stop the tractor and if it's not all the way down the tractor of course will not start. So I tap the pedal without even thinking about it to ensure the lever is far enough down. I guess this habit has carried over to my 3750 as well. But right or wrong that is what I do and I guess thats why I tap the pedal. There is no other logical reason that comes to mind thats for sure.
But I do always use the glow plugs if the engine is cold.
They start every time. Gordon

 

[MChalkley]

Re: Starting Kubota...Gordon

Gordon, I'm a firm believer in the theory that you can't argue with results. If you've been starting them that way that long and they continue to start, you just keep on starting them that way. /w3tcompact/icons/smile.gif

Mark

 

[Kubota-monkey]

It is a good thing to slightly raise the rpm on the tractor before starting. More fuel will rush into the engine and flush out any particles left. SInce I live in Northern New England I also have a problem with cold weather starting. I turn up the rpm and after it starts turn the rpm way down and let my L35 idle for about 20-30 minutes when it is 0-20 degrees.
Alan it seems to me that you live in a much warmer climate. I do notice in the summer that I dont have to boost the rpm but it is still a good thing to do anyway.

Good Luck!

 

[Bird]

Kubota-monkey, I don't guess you'd have to know a whole lot to know more than I about diesel engines, but I still disagree. It seems to me that starting a cold engine, whether gasoline or diesel, at higher RPMs simply means more friction (more parts rubbing) and more wear before the oil pressure comes up and it gets to circulating to lubricate everything. As far as flushing out any particles; are you kidding?/w3tcompact/icons/smile.gif Now admittedly, my manual says to open the throttle half way; and there's just no way I can get myself to do that to an engine. My B2710 was delivered idling at 1200 RPM and I backed it down to 800-900 when it's warm, but it'll start very easily cold at about 600 RPM and then after just a very few seconds, I'll open the throttle to 1200-1400 to let it warm up a bit.

Bird

 

[Von]

Bird, On my B8200 the book states to warm the glow plugs for 30 sec. above 32 and for a full min. below 32. And believe me, you do have to wait the full min. when its cold out! Even in the warmth of summer it still takes the 30 sec. for it to start right up. I guess they have made some advances in starting on the newer tractors. Von

 

[Bird]

Yep, they really have made some changes. I've helped a neighbor bale hay with his old tractors and it'll take full minute sometimes before they'll start, I think my 1995 B7100 was about 10 seconds and now the B2710, 2 to 3 seconds; quite a difference.

Bird

 

[MChalkley]

Bird, I agree with you. Years ago, I took diesel mechanic classes and, while nothing was said specifically about throttle position when starting, a lot was said about friction, oil pressure, and the like. So, as you say, the lowest rpm that it will start at reliably and quickly is the one I want to use. For my L4310HST, that's 900 rpm, which is as slow it goes. Below 20 degrees or so, if it won't start after 5 or 6 revolutions (which is rarely), I open the throttle a little, then close it immediately after it starts until it's run a few seconds to build the oil pressure, then open it back up to 1200-1500 rpm to warm it up.

Mark "SPCT" Chalkley

 

[PaulB]

Mark - my guess is Society for the Prevention of Cruelty to Tractors ???

 

[MChalkley]

PaulB - no moss grows on you, eh?

Mark