Hard to turn engine over A ford 1929

[Jacksonlll]

Something easy you can try. Looks like you have the 12 volt cables on there. They can't handle the current of a 6 volt system. Leave it as it is and put a jumper cable between the negative post and the starter. This will give you, essentially a bigger cable that should carry the current for a test. All you probably need is the 6 volt cable that the guys have been telling you. Try it.