How to start a 6 volt with a 12 volt

FYI - Alberta Mike is right about the cable sizes.

Here's why - every wire has a small ammount of resistance to the flow of electricity. This resistance is proportional to both length and wire diameter. (i.e. smaller diameter = more resistance, longer wire = more resistance). Resistance takes electrical power to overcome it (usually producing heat).

Since your battery voltage is fixed, the resistance limits the current the wire can carry. (Damn, couldn't avoid the algebra: remember V=IR) Other people may talk about a voltage drop along a wire - same thing, different way of looking at it.

In a 6V system, your starter requires twice as much current (amps) as in a 12V system. The end result of all this is that a 6V system requires larger diameter cables to supply adequate power to the starter. Shorter cables helps as well.

If I'm clear as mud - Claus and/or Zane have some good posts regarding this in the archives.

First, MAKE DARN SURE THE TRANSMISSION IS IN NEUTRAL! You'll be bypassing the start in gear interlock and standing in the way of that big rear tire. Ugly combination if the tractor is in gear when it starts.

1) Hook the jumpers up to the 12V battery.
2) Connect the + cable to the tractor "frame" somewhere near the starter where it can make good contact. (technically polarity here doesn't matter)
3) Double check that the tractor is in NEUTRAL!!!
4) Turn the ignition switch on and set the throttle
5) Now for the manual starter switch: Touch the - cable to the post on the starter. Be ready with the choke in the other hand (having a second person helps). The engine should crank - once it fires pull the cable away from the starter and disconnect all cables.

After its running I'd head back to the barn to figure out why it died - you don't know how long the 6V will run the ignition circuit. On mine both the generator and battery were bad and I ended up converting the whole thing over to 12V rather than rebuilding the generator (it was cheaper).

Greg