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I'm not aware of any after market alternators with geared tachometer connections to fit the Continental engines. I have a MF-135 with a generator. Going to a tach you almost surely have a different pulley on the alternator (you need to spin it faster anyway) than the generator and a wider pulley than is standard on car alternators. That wrecks the tachometer calibration. Then you need the direction of rotation of the gears (as well as the speed change) to match the rotation of the tachometer that could have been run from the back end of a gear driven cam shaft. There's no way to get to the camshaft of the Continental engine either. The generator on my MF-135 works quite well so I've not seriously considered changing it. It didn't charge well when I first got the tractor in 1987, but it had a new voltage regulator. I lifted the cover off that voltage regulator and tweaked a spring anchor to raise the voltage slightly and I get 4 or 5 years battery life and rarely have to put a charger on it, even with light use. I have a bigger tractor for field work now. The tachometer option I've considered most is to go to an electronic tachometer (loosing the hour meter, but my MF-135 has a separate hour meter anyway) driving from the ignition system. There are a few with digital readout in 10 RPM increments that would work well (maybe in the J.C. Whitney catalog though I don't know if they will stand being rained on). Most of the pointer styles for hotrods don't get to full scale at 2500 RPM, unfortunately more often at 8000 or 10000 RPM which makes the tractor range almost useless. I'm sure the 10000 RPM tach with a new scale and a slight circuit modification would work super on the tractor. I probably could do it, but I've not tried it. The problem would be mostly in opening up the package and closing it again neatly, not in modifying the electronics. Might only need to be set for a single cylinder 4 cycle engine on a switch and then the modified scale. There might be a mechanical option but it could be messy to make work. One could build a gear box to ride a pulley on the inside of the fan belt above or below the alternator, then adjust the geared speed to calibrate the original tachometer. Or one could put that pulley on the OUTSIDE of the fan belt, but then the pulley would have to be larger and you'd have to change the pulley to set the tachometer calibration. I suppose one could build a very custom distributor and bring out a shaft at a suitable speed for the tachometer (like the distributor drive of my JD 4020 gas engine). Or one could scrap the alternator and put the original generator with proper gear box back on. Gerald J.
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