PTO RPM

[solder]

Does anybody know the engine RPM that produces 540 at the PTO. I have a Tractor King FT 404 3 Cyl. I'm guessing 1500-1700, be nice to know.

[Rich Waugh]

You'd have to calculate all the blasted gear ratios to get it exact, but it really doesn't matter all that much. Most Chinese tractors show a green area on the tachometer which is where your engine should be running to get the proper PTO speed. On my Jinma 304 that is about 2000 rpm, more or less.

Alternately, you could pick up a cheap optical or mechanical tach from Harbor Freight and get some actual numbers.

Rich

[bradblazer]

It looks like the rated RPM of your tractor is 2200RPM. The PTO speed is normally calculated that RPM. Like Rich said - there should be a green band on the tach.
www.farmprotractors.com/FarmPro/Farmpro_4020.asp?ID=Specifications

[traktorz]

I think your engine is SL3105BT, delivering the rated power 29.4kW at 2200rpm.

From the Owner's Manual, I'm reading:
Note: the speed of the power take-off shaft described here is the speed when the engine runs at a speed 80~90% of the rated speed. Therefore assume 540/1000 at PTO when engine runs at 85% of 2200 rpm = 1870 rpm.

[3RRL]

Don't forget to take advantage of you 40 hp and the second PTO speed of 1000rpm.
I frequently run my PTO equipment in the higher range and reduce engine rpm's so that the PTO is spinning 540 in high range. It is very handy when doing light mowing or other light duty PTO equipment that does not need the torque and horsepower associated with the 540 PTO range. It saves a lot of fuel and wear and tear on the engine and other components.

On my Kama, when I run the PTO in the higher range, my engine rpm's are around 1750. This is optimum for my engine since it makes it's peak torque at about 1650 engine rpms. So that means I still have maximum torque available running at that engine rpm. When it starts to bog down a little, the engine rpms start to fall back towards the peak torque and the engine surges back to 1750rpm.
Rob-