If you have power to the small post on the solenoid when you turn the key to "start", I would suspect that the solenoid is junk. The other thing to check would be that the solenoid is well grounded. run a jumper wire from the metal case or mounting bracket of the solenoid to Battery - and try again. If it still won't crank, do like Mike said, take a old pair of needle nose pliers that you don't care if you ruin (the current of what your about to do can possibly weld them together), open the pliers and stick the tips to the 2 large terminals of the solenoid. this should get the engine to spin over (even if the key isn't on). I've never worked on a Mudd-ox so I don't know what type of solenoid it has, but many machines come with a CHEAP lawn and garden type. If this is the case, replace it with a ford type. Note: the lawn and garden ones have 5/16" terminals, and the ford ones have 3/8 so you will have to change the ring terminals on your wires. Also the connection for the small wire will probably be different.
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