We have always had to back the throttle down as we sho ed the torque amplifier up with our 886 or the front end would’ve lifted off and probably slammed our heads against the back
Not sure if that tractor is wired the same as our 1066, but on it there is a resistor behind the plate by the park brake that some how is tied in between the switch and the alternator, anyway if it goes bad or a dang rat chews the wire into it doesn't charge.
806 gas was our plowing tractor when I was a kid. Pulled five bottoms with a rack of weights up front. The old tractors can do a lot more work than the equipment sales companies convince young farmers. The biggest power they pull: you can buy them for cash, do some little repairs, and start making money not feeding the financing banker game.