I own a TO-35 and had the same feelings you do. I wanted to get on the tractor, turn the key, push the button, and have that tractor start every time, with substantial cranking RPMs from the starter motor. That is why I put an 8 volt battery on my 6 volt system. I did this about 3 years ago, and it has worked flawlessly. However, I made a few modifications as follows. 1. I added 2 diodes in series with the primary side of the coil, and a 6 volt relay whose coil is paralleled to the startor relay coil, to jump out the diodes when you start the tractor. This does 2 things, it allows a full 8 volts going to the coil when you crank it, producing a much better spark.....and after it starts, the relay drops out, the contacts across the diodes open, and you get a voltage drop across the diodes of approx. 1.4 volts. This lets the coil get about 6.5 volts when running, so you don't burn up the points or the coil. I think you could also use a balast resistor instead of diodes to accomplish the same task. (Like the old 6 volt cars?) 2. I added resistors in series with the charging relay coil and cut-out relay coil in the voltage regulator. Originally the charging relay picked up @ 6.9 volts. This was the point that the regulator switched from "full charge" to "trickle charge". With the resistor in series, the relay now picks up @ 9.2 volts, allowing a higher charge to the 8 volt battery. The cut-out relay originally picked up @ 6.4 volts. This was the point at which the generator armature ties into the battery circuit to start charging the battery. By adding the resistor, this relay now picks up at 8.5 volts. I bought my 8 volt battery from Central Tractor and the other parts I got from junk I had laying around. I thought about going to a 12 volt system, but that would be more costly and I wanted to try to keep the tractor as original as possible, but still have a great starting machine. One last thing are the lights on the tractor. I very seldom use them, so I did nothing to address the 6 volt bulbs running on an 8 volt system. I hope this helps..it can be done if you decide to go this route.
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