340 wont start when hot

[farmall66]

have a 340 wont start if you cut it off when hot runs great plenty of power.starts great cold. have all ready replaced coil cap rotor points and cond.thanks

 

[Janicholson]

Put heavier 0gauge battery cables on it. You can test this theory with a jumper battery hooked to ground, and the starter relay. this adds amp capacity when testing. Jim