Anonymous Poster
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Re: Swapping GST to HST-Maintaining PTO Speed
<font color=blue>...Someone posted you should run these tractors at a constant speed on the engines instead of using a foot throttle as much. Anybody know why? ...</font color=blue>
Using any PTO driven implement, remember the PTO drive shaft should be going 540 rpm {ASAE industry standard}. Check your engine tach, for the 540 rpm mark...
Each tractor will be slightly different, on my Massey 135 & 165, it's 1689 rpm; the Satoh is 2500 rpm; and JD is 2200 rpm.
Most groundwork is done between 2 - 8 mph; avg. fieldwork is 5 mph optimum. Check your owners manual, your rear tire sizes, and generate a "mph chart" @ 540 PTO/rpm to stay within these ranges.
For example, you're in low range, 4th gear @ 2200 eng/rpm with 16.9 - 28 rear tires going 5.52 mph with the PTO implement going 540 rpm... If you decide to "Throttle down" to 1500 eng/rpms, your PTO drive shaft slows down to 400 rpm... now cutting even 1-2" brush becomes a nightmare if not impossible...{now your PTO HP is half as much}
So instead, you want to "Gear down" to say 2nd gear, keeping the same engine rpm @ 2200 eng/rpm, in turn keeping the PTO shaft going @ 540 rpm, but now your traveling speed is 2.79 mph.
Remember that '540' mark on the tach is the sweet spot for PTO HP, lower means less HP to do the job as well as non-standard slower PTO drive shaft speeds.
<font color=blue>...Someone posted you should run these tractors at a constant speed on the engines instead of using a foot throttle as much. Anybody know why? ...</font color=blue>
Using any PTO driven implement, remember the PTO drive shaft should be going 540 rpm {ASAE industry standard}. Check your engine tach, for the 540 rpm mark...
Each tractor will be slightly different, on my Massey 135 & 165, it's 1689 rpm; the Satoh is 2500 rpm; and JD is 2200 rpm.
Most groundwork is done between 2 - 8 mph; avg. fieldwork is 5 mph optimum. Check your owners manual, your rear tire sizes, and generate a "mph chart" @ 540 PTO/rpm to stay within these ranges.
For example, you're in low range, 4th gear @ 2200 eng/rpm with 16.9 - 28 rear tires going 5.52 mph with the PTO implement going 540 rpm... If you decide to "Throttle down" to 1500 eng/rpms, your PTO drive shaft slows down to 400 rpm... now cutting even 1-2" brush becomes a nightmare if not impossible...{now your PTO HP is half as much}
So instead, you want to "Gear down" to say 2nd gear, keeping the same engine rpm @ 2200 eng/rpm, in turn keeping the PTO shaft going @ 540 rpm, but now your traveling speed is 2.79 mph.
Remember that '540' mark on the tach is the sweet spot for PTO HP, lower means less HP to do the job as well as non-standard slower PTO drive shaft speeds.
