Honda533

Found issue and I’m guessing this is common on all the 700’s as well as maybe the 500’s On the main harness there is a white plug to the front right of the motor. The plug is where the engine harness begins and goes to the ECU all the sensors, throttle body, fuel pump, stator and a few more engine related items. The plug lays on the floor board and ends up wet and muddy. This causes corrosion. On mine the pin that supplied the 12v to the ECU was only hot on one side of the plug . The other side was less than a volt. Tried cleaning the plug but it didn’t help. Had to splice the wire that was bad which in my case was just the one. All the other wires were checked for continuity and verified good. Got spark back and fuel pump.

Found issue and I’m guessing this is common on all the 700’s as well as maybe the 500’s On the main harness there is a white plug to the front right of the motor. The plug is where the engine harness begins and goes to the ECU all the sensors, throttle body, fuel pump, stator and a few more engine related items. The plug lays on the floor board and ends up wet and muddy. This causes corrosion. On mine the pin that supplied the 12v to the ECU was only hot on one side of the plug . The other side was less than a volt. Tried cleaning the plug but it didn’t help. Had to splice the wire that was bad which in my case was just the one. All the other wires were checked for continuity and verified good. Got spark back and fuel pump.

Machine sat and had multiple rodent chews thru out the wiring that we fixed. Also replaced the Following: ECU, Coil and Plug Wire, small Control Box that contains fuses and relays. Pick Up coil test at 219 ohms which is typically good on most machines but i can't find the specific manual on this thing to get the spec. Battery good, cranks fine but the fuel pump doesn't prime or run and no spark. Tested pump with direct 12volts and it works. If we supply a ground to the pump it primes and works but still no spark. We have traced all wiring including grounding and all is good. Tested key switch. I has (4) positions. 1 - off, 2 - does nothing, 3 - powers up everything (lighting and odometer and powers ECU, 4 - starts engine. The key switch only has 3 wires. 12v in from battery and 2 - 12v out which is power to the system and send 12v to starter relay coil. Are these electrical systems actually switching the grounds on and off vs the traditional switching the 12v+ on and off. at my wits end with this thing. Also when we figure this problem out we will post the solution. seems 90% of people that ask for help on these forums, never post the fix which make this pointless.