What RPM should I use to mow

garry · May 30, 2016

I have a 1997 Steiner 430 Max with a 20hp Onan. It has a 5 foot mower deck. This is my first year to mow with it. What RPM should I be running when I am mowing?

motownbrowne · May 30, 2016

I'm not familiar with that particular machine, but most small engines like to be run at WOT, or pretty darned close to it, for a power intense application like mowing.

garry · May 31, 2016

I have the Operator's Manual but it does not address RPM operating speeds.

buickanddeere · May 31, 2016

Wide open throttle . That is where the engine makes peak power, peak cooling airflow , no lugging which wears parts and highest blade tip speed to cleanly cut the grass .

Gary Fowler · May 31, 2016

I cant think of any small engine driven mower that isn't supposed to be ran at full throttle. You need that RPM to get the blade tip speed up high so it cuts cleanly and discharges cut material cleanly. You may also need the high RPM to get proper function of the drive motors on hydrostatic driven machines.

Tractor PTO driven mowers need to be ran at the rated engine speed that produces the correct PTO speed, usually 540 rpm for rear mounted mowers. This speed will be marked on the tachometer and may be wide open throttle or in some instances a few thousand RPM less than full throttle. This speed is usually marked at the speed the engine delivers peak HP. You may be able to throttle back a bit from this setting IF you have plenty of power for the mower AND you continue to get acceptable cutting results.