Mow Using 960 PTO Setting?

[repete]

I also have a 4" hand grinder to sharpen the blades. To do this I attach the deck to the bucket by first wrapping a chain around where the top link connects. I then put the top of the bucket up against the point where I have attached the chain. I have a center hook welded on to lift by.

The next step is to lift the deck off the ground. By tilting the bucket back you can expose the underside of the mower deck. You can then stand and sharpen the blades.

BE SURE TO PLACE THE DECK ON AN IMMOBILE OBJECT SO THAT IF SOMETHING FAILS, THE DECK DOES NOT COME DOWN ON YOU! NEVER WORK ON SOMETHING THAT WOULD KILL YOU IF A HYDRAULIC LINE FAILED OR SOME OTHER TEN CENT PART GIVES WAY!

 

[Chilly807]

BP,

If I were guessing, which I'm not, I'd think you're trying to get through the break-in period without running at steady full speed with little load. If that's the case, then I understand where you're coming from. Mowing is tough on a new engine, in that it limits your speed to a constant steady rate, instead of varying speed and load as most recommend.

Having said that, I bush-hogged about 20 acres with my L3400 with about 20 hours on the clock. It had to get done, and it was the only tractor I had to do it with. I did try to vary the rpm a bit, between 1800 and 2400 (my 540 PTO speed is about 2350). Also, stopping and backing up for corners, I dropped the rpm for a few seconds, then continued. Letting the engine idle for a minute after every ten minutes of mowing might not be a bad idea either in your case.

I did make sure that when I went through heavier grass that the rpm was close to where it was supposed to be to avoid lugging the engine.

If it were me, I'd run the PTO at the correct speed and vary the engine rpm a bit, rather than use the 960 setting. I assume the mower calls for 540? If so, overdriving it won't help the cause, though it will undoubtedly do a great job of cutting the grass. Running the engine speed lower to get the correct PTO speed won't do the engine any favours either, but as long as it's not lugged it shouldn't hurt it. How much more does it labour starting the mower at 960 than 540?

Sean

 

[bp fick]

Sean,

Actually, got three or four neighbors who do light brush hogging using the faster PTO speed to keep the engine RPMs down. They all claim they like the lowered noise, and see no need to do anything different. Some claim to have done this for hundreds of hours.

I honestly don't mind running at 2600 or 2700 which would run the RFM. Again, this is very thin grass on the lawn. We don't have thick grasses on the sand base up here.

I just thought I'd try it. I mowed some at 540 setting with engine at 2700 and some at 960 with engine at 1700. Yeah, it's nicer with the engine not roaring. I had no sense that the engine was lugging at 1700, but again, this is new to me. Never even had the option before.

 

[Transit]

BP,

If I were guessing, which I'm not, I'd think you're trying to get through the break-in period without running at steady full speed with little load. If that's the case, then I understand where you're coming from. Mowing is tough on a new engine, in that it limits your speed to a constant steady rate, instead of varying speed and load as most recommend.

Having said that, I bush-hogged about 20 acres with my L3400 with about 20 hours on the clock. It had to get done, and it was the only tractor I had to do it with. I did try to vary the rpm a bit, between 1800 and 2400 (my 540 PTO speed is about 2350). Also, stopping and backing up for corners, I dropped the rpm for a few seconds, then continued. Letting the engine idle for a minute after every ten minutes of mowing might not be a bad idea either in your case.

I did make sure that when I went through heavier grass that the rpm was close to where it was supposed to be to avoid lugging the engine.

If it were me, I'd run the PTO at the correct speed and vary the engine rpm a bit, rather than use the 960 setting. I assume the mower calls for 540? If so, overdriving it won't help the cause, though it will undoubtedly do a great job of cutting the grass. Running the engine speed lower to get the correct PTO speed won't do the engine any favours either, but as long as it's not lugged it shouldn't hurt it. How much more does it labour starting the mower at 960 than 540?

Sean

Cutting light grass at low rpm may be ok, but if the PTO is running faster than 540 you are asking for trouble. The stored energy is proportional to the square of the speed, double the PTO speed and energy goes up 4 x normal, a bit hard on the gear box, devastating on the blade bolts and blades. You risk launching a blade at 100 mph across a field to say nothing of the out of balance hog.

 

[DonnieP]

I run high speed on PTO selector a lot of the time while mowing light stuff and even on the snow blower if the snow is light. My math: 540/960 = 0.5625 2700 x 0.5625 = 1518 rpm will give you 540 rpm at the mower using the 960 rpm selection. It's much easier on fuel, easier on the ears, you're not hurting the mower, you're running it at the correct speed, and if you listen to the tractor, and watch the signs like repete says, you can tell when the load gets heavy, change pto range and rev her up

 

[kuboman]

Sean,

Actually, got three or four neighbors who do light brush hogging using the faster PTO speed to keep the engine RPMs down. They all claim they like the lowered noise, and see no need to do anything different. Some claim to have done this for hundreds of hours.

I honestly don't mind running at 2600 or 2700 which would run the RFM. Again, this is very thin grass on the lawn. We don't have thick grasses on the sand base up here.

I just thought I'd try it. I mowed some at 540 setting with engine at 2700 and some at 960 with engine at 1700. Yeah, it's nicer with the engine not roaring. I had no sense that the engine was lugging at 1700, but again, this is new to me. Never even had the option before.

To maintain 540 rpm requires a slow engine rpm usually below the recommended rpm for proper engine operation under any kind of load. Also you run the risk of accidentally overspeeding and doing serious damage to your implement. Just my 2bits