Novice tractor owners bring this up quite often. They don't realize that both the tractor and implement manufacturers engineer their products to work most efficiently at specific speeds. When you run the tractor at less than PTO revs (as indicated on your tachometer) you risk unnecessary engine and drivetrain wear when the implement drags the revs down below the effective range on the torque curve. Matter of fact, my new JD has a feature that automatically increases engine output when it senses more throttle is needed to maintain adequate output torque - without any input from the operator. So you're
not actually
running the **** out of your engine, it's truly designed to work that way.
720 and 1000 PTO speeds are not typical for compact and utility implements in this country, so you'll likely have no practical use for either. And PTO driven implements are designed around the concept that they works most efficiently when the tractor engine is producing revs that generate 540 rpms at the PTO output. My wood-
chipper for example; it might sound as if there's too much engine when the
chipper is eating twigs and leaves. But as soon as it sucks in that 5 inch diameter limb, I'm **** glad she's running at PTO revs. In addition to the torque factor already mentioned, it relates - in the case of mowers for example - to blade tip speed.
Getting creative with manufacturers recommendations about engine revs and PTO speed selecting will do nothing to extend the life of your equipment, in fact can actually shorten it. And in many cases you'll likely be less than satisfied with the work product as well.
But to address your actual question, it's possible - but
not easy. Dong Feng sells worldwide, so they could likely (eventually) provide you with the necessary 720 drive gear(s). Don't expect to find them here in America though, they would probably have to be sent from China. But that's the easy part. With gear(s) in hand, you'd then have to split the tractor in half, remove the transmission from the rear half, and remove/disassemble the entire PTO driveline - just to swap a couple gears.
//greg//
