Stalling the engine under load?

[bikerdib]

Could be the soil I'm in; clay/sand mix. This soil lets the ties dig in pretty good but still has enough consistency to give good traction instead of just being dug out by the tire lugs. The few stalls have been when I was using the sub-soiler to bust roots so there was extra down force on the rear tires. I think one stall came when I was pulling down a tree with a chain.

I hope to do some more work this weekend. I'll see how things go after I adjust the pedal return damper and also give more throttle. I really think the pedal return was the biggest problem; it wasn't letting the drive release fast enough when I took my foot off the forward pedal when I heard the engine start to slow significantly. I had adjusted the pedal return springs but like I said, I didn't know the damper had an adjustment also.

 

[JoeL4330]

I know that for using the PTO there is the recommended RPM mark on the tach. But for pulling and such, if I run the throttle control all the way to the stop, there is no chance on over revving the engine? Is that the recommended way to work it?

In my searching, I was never able to find what the recommended max RPM is and there is no red line mark on the tach.

I have posted on this before...if you look at a torque curve you will see that it rises with rpm to a max, and then declines slightly ...your machine is set so that the rpms that make 540rpm at the pto is just beyond the torque peak ...probably 2450 or so ...it is so designed to be on the "back side of the torque curve" so that it something starts to bog down your engine, your rpms start to drop and your torque actually increases, allowing you to safely power through small "excess" loads without stalling.

And, for the same reason, that is the sweet spot when you want to do hard work ...and, no, you can't over-rev with the throttle (although if you were using the PTO you could over-speed it and work outside the safe range of your implement. But, unless you especially want to increase PTO speed (and know what you are doing) there is no reason to rev higher than the sweet spot ...revving higher will, as stated, increase the PTO speed, and it does increase horsepower ...but it's the torque that does the work. So, hard work at 2450, or so...and, yes, get the HST pedal damping set to suit your preference (although I don't recall reading about such in the shop manual ...but, I'll look) ...let us know if things improve at max torque.

One more thing, as posters have said stalling the engine is not good, nor is hitting something that stops you dead ...my back blade has a hydraulic cushion valve in its hydraulic angle circuitry in case an edge catches an immovable object...and, snow plows have trip springs, etc. ...so, if this is a continuing problem for you then you might consider some sort of shock absorber...usually wheelspin comes to the rescue, but seems like not in your case

 

[savageactor7]

I've taken down trees up 4-5" using the FEL. I dig up one side and with the FEL loaded with sand I raise it all the way up and push against that same sided and push the tree over...that way it's pretty easy to get the rest of the roots.

Anytime you're working the tractor hard imo it's best to keep the RPM's up close to PTO range that way you have power/torque and don't have to depend solely on momentum.

 

[bikerdib]

OK, here is the follow up after I did some more work this weekend.

First, I adjusted the pedal return damper to provide minimum resistance to the pedal returning (it now returns pretty much unrestricted). I prefer it this way for doing "heavy" pulling and also for mowing in tight areas. With it set this way, I can stop the drive immediately if needed by simply removing my foot from the pedal or in non "emergency" situations I can slow down as gradually as needed using pedal control. By the way Joel, The reason I didn't set this before is, like you, I looked in the shop manual and they don't mention it there; I only found instructions about setting the return spring. I found the damper setting instructions in an owner's manual.

Second, I ran the throttle at the RPM speed setting when I knew I'd encounter heavy pulling. It's amazing how much extra torque the 500 additional RPM provided. Now most times before the engine really even starts to bog, the front & rear tires start spinning instead.

No more stalling; in fact, I didn't even come close.

 

[JoeL4330]

Yep, the torque curve on a diesel is quite steep ...until it peaks (at 2450 or so and turns down)...can you be more specific about the damper info? where can I find...where would I adjust

 

[bikerdib]

This is the info I was able to find on my B7300. Of course your "L" might be different.

 

[JoeL4330]

thnx much ...will check mine in the AM and compare

 

[MMH]

Sounds like the OP is not familiar with the HST operation.

Think of HST and the forward pedal as going from a lower to higher gear when pressing the forward pedal. Pushing harder on the pedal reduces the engine power and when you encounter higher/more load (filling the bucket with dirt for example), let off on the forward pedal to drop into lower gear (so to speak). That will avoid killing the engine.

Best explanation of hydro operation & I own a gear tractor.

 

[IdahoTractor]

. . . . Then I use a ladder and get pretty high up on the trunk (depending on the size of the tree) to attach a cinch chain to which I then hook my pull chains. To give the tractor and chains some buffer I run the tractor at about 66% to 75% of max RPM. . . .

I'd be more concerned about the chain busting apart and injuring or killing me than the engine stalling. To keep the chain from whip-lashing back at you, be sure to drape a blanket or coat somewhere between the object you're pulling and the midpoint of the chain.

 

[edwinwil]

amen brother God bless