I have a john deere 757. My first problem is when I cut for about 20 minutes the blades will disengage. I let it set for about a minute then I can cut for another 2 minutes. The same thing again. Now, the last time that the blades cut off I cut the motor off and it will not do anything now. We checked all the wires they look good. The starter was red hot. Got fire to the started but it will not engage when jumped. Might have multi problems now. What do you think?