Rong, as I understand it the speed of Greenfield mowers is set by a combination of the engine speed and the degree of clutch slip. Engine speed is adjusted by the "speed control", which controls the set point of the governor: there is no user-accessible throttle on Briggs engines, just a speed control. The engine speed should be set as low as possible without risk of the engine bogging down under the load applied, so you would need to adjust it when you change slope, length of grass, etc. The other ground speed adjustment mechanism is slipping the clutch. Instead of having a multi-speed gearbox, Greenfield uses large clutches, which are slipped most of the time. I think some other mowers use the same approach. The concept of slipping the clutch continuously is an unfamiliar one to those of us who drive cars with manual transmissions, but realistically a Greenfield has a car-size clutch on a low-geared, low-powered, light-weight machine, and they seem to go for a number of years between clutch re-lines, even when used every day by mowing contractors.
I'm very interested in getting Greenfield technical information uploaded to our manuals section. Perhaps you could let me know what you have (that Greenfield has authorised you to upload) by Private Message and we can see what process will work best.
Last edited by grumpy; 11/10/12 07:57 AM. Reason: Add note on data upload
