Quoted:
I doubt that an 18hp tractor has a PTO that turns at 3,600 RPM to run that genset. And I know it doesn't have the power to run an 10,000 watt at full draw.. I'd check your trator specs and then go to northern tool and pick out one that will work. Good Luck, I just looked into the same thing for my own situation.
RPM:
as noted above, typical tractor PTO speeds are 540RPM and 1000RPM. an attached 60Hz generator as to spin at either 1800RPM (4 pole type) or 3600RPM (2 pole type). so a gearbox or pulley arrangement is required to convert RPM's.
POWER:
in general, you will need 2HP at the PTO for every KW of power output at the alternator head. again, this is HP at the PTO and not engine HP. direct gear driven PTO's are usually about 90-95% of engine HP, while hydrostatic (HST) driven PTO's are usually about 75-80% of engine HP.
ar-jedi