What is the Correct RPM?

[Indian MC]

Thanks, It sounds like I'm doing everything right by just varying the RPM's the best way the tractor feels comfortable relating to what I'm doing.
The marking " square orange " block on the RPM gauge around 2900 concerned me.
There's no mention of that mark on the tach in the manual. I thought maybe it was the sweet spot for everyday use.
I don't have any PTO implements, if that is what the mark is for.
Just the FEL and Backhoe for now.
Thanks again,

 

[chim]

Most of my seat time in the warmer months is spent mowing with the RFM. I use whatever engine speed it takes to get the mower to cut well and distribute the clippings nicely. This varies with the condition of the grass. Last night that was around 1700 RPM. I fertilized recently and we've had a lot of rain here so far this Spring. The grass was juicy and fairly dense. As mentioned, with certain operations you need more power from higher revs. Other times you need to slow things down a little to make movements a bit less twitchy.

 

[Fallon]

Thanks, It sounds like I'm doing everything right by just varying the RPM's the best way the tractor feels comfortable relating to what I'm doing.
The marking " square orange " block on the RPM gauge around 2900 concerned me.
There's no mention of that mark on the tach in the manual. I thought maybe it was the sweet spot for everyday use.
I don't have any PTO implements, if that is what the mark is for.
Just the FEL and Backhoe for now.
Thanks again,

Most machines have a mark on the tach. It's the engine RPM that corresponds to the standard 540 RPM on the rear PTO shaft. Usually its somewhere north of 2,000rpm & near the top of the throttle range.

They generally design things so PTO RPM (540) is a little past max torque. That way you are pushing the engine into max strength where it can recover rather than into a condition of less power & ending up stalling easier. It's not that big of a deal for HST machines as you can just ease of the go pedal a hair & keep on going.

 

[CobyRupert]

Most machines have a mark on the tach. It's the engine RPM that corresponds to the standard 540 RPM on the rear PTO shaft. Usually its somewhere north of 2,000rpm & near the top of the throttle range.

They generally design things so PTO RPM (540) is a little past max torque. That way you are pushing the engine into max strength where it can recover rather than into a condition of less power & ending up stalling easier. It's not that big of a deal for HST machines as you can just ease of the go pedal a hair & keep on going.

I was going to say that there's nothing magical about 540 PTO rpm. It's just a number. The only thing special about it is the mark on the tachometer.

However, you make a good point if the engine torque is curved like you say (in relation to PTO rpms) and you need maximum torque, or there's something special (rpm dependent) about the implement (maybe it has a hydraulic pump that needs a certain flow, or blades that need tip speed, air flow, etc...). However most implements don't care as long as your within a wide range, as long as you have the torque to turn them and ground speed is appropriate, and most importantly, you get the results you want.

 

[ptsg]

On my tractor the 540 PTO RPM is set close to the HP peak of the engine (2500 RPM) and the 540E is set at the torque peak (1800 RPM).

 

[wisconsitom]

Bump;. On my 25 horse BobKioti, I've got a forestry skidding winch on the back which runs off pto. My understanding is that 540 revs is max that implement wants to see, not what it needs. It's also my understanding that things get gnarly in a hurry when one goes much above idle when skidding logs! Nor is more throttle typically needed.

Am I wrecking something? I don't know, but running these things at a low idle is commonplace.

 

[ROUSTABOUT]

The faster the engine turns, the more hours on the hour meter. 12-1400 is fast as I ever go.

 

[rScotty]

Bump;. On my 25 horse BobKioti, I've got a forestry skidding winch on the back which runs off pto. My understanding is that 540 revs is max that implement wants to see, not what it needs. It's also my understanding that things get gnarly in a hurry when one goes much above idle when skidding logs! Nor is more throttle typically needed.

Am I wrecking something? I don't know, but running these things at a low idle is commonplace.

That's the way I run them too. Low and slow.