In Reply to: Starting a rebuilt engine posted by Chris Libby on April 16, 2020 at 22:22:37:
You want to make a simple loop directly to the starter. I would first add a second nut on to the threaded post that powers the starter. This way you will not damage the threads when you jump to it because you can hit the nut and not the threads.
Also, I would use a separate battery so you can connect directly to the posts on the 12 volt battery. Connect positive post on battery to tractor frame/ground close to the starter. Make very sure tractor is NOT in gear. Then connect jumper cable to Negative post on battery and then tap other end of jumper cable to post that powers starter. You should get a good spark and starter should bump. Then do the same, but hold Jumper onto starter post to see if it cranks.
I have heard of folks that have a tight rebuild and have had to pull the tractor when in high gear to get it to spin and loosen up. Make sure you have plenty of oil in everything.
Good luck. Be safe.