No Spark 1996 175 EFI, just rebuilt

[mopractice]

Hi, looking for help/advice

175HP Mercury EFI OG 429313
Engine seized last summer (oil injection drive gear on crank broke), I finished the overhaul and now have no spark on starboard side and weak spark on port side.
I tested the stator with an ohm meter and all readings fall in the mid range of what is shown in the manual. Also tested the trigger and it shows good. I installed new
voltage requlators because they looked baked.

Is there any thing other than the stator that affects spark? Finding it hard to believe that the stator is bad, it was working before the rebuild. I ordered a DVA so I can do the other tests
shown in the manual, should arrive today or tomorrow. Any suggestions or other things to test?

I also removed the drive shaft for the oil pump and will be running mixed fuel

[rhardwick]

A bad switch box can do that also. You can try switching the switch boxes and see if the issue reverses itself. If you disconnected the switch boxes make sure the wiring with yellow bands goes to the inside switch box. A bad bias circuit in one switch box can affect the other one.

[Bodhi]

Yep, your switchboxes are shot. Pop 2 new in and you'll be up and running

[flabum1017]

did you try checking the spark with the harness disconnected from the boat?

[bullet123]

A bad switch box can do that also. You can try switching the switch boxes and see if the issue reverses itself. If you disconnected the switch boxes make sure the wiring with yellow bands goes to the inside switch box. A bad bias circuit in one switch box can affect the other one.

yellow sleeve goes on outer box

[bullet123]

Hi, looking for help/advice

175HP Mercury EFI OG 429313
Engine seized last summer (oil injection drive gear on crank broke), I finished the overhaul and now have no spark on starboard side and weak spark on port side.
I tested the stator with an ohm meter and all readings fall in the mid range of what is shown in the manual. Also tested the trigger and it shows good. I installed new
voltage requlators because they looked baked.

Is there any thing other than the stator that affects spark? Finding it hard to believe that the stator is bad, it was working before the rebuild. I ordered a DVA so I can do the other tests
shown in the manual, should arrive today or tomorrow. Any suggestions or other things to test?

I also removed the drive shaft for the oil pump and will be running mixed fuel

remove bias wire between boxes and see if your spark returns

[rhardwick]

I stand corrected on the yellow tape, been a while since I've messed with switch boxes.

yellow sleeve goes on outer box

[25two.stroke]

I know everyone is throwing out different ideas right now but PLEASE:
CHECK ALL THE WIRES ON THE SWITCHBOXES AND MAKE SURE THEY ARE ON THE CORRECT TERMINALS
It sounds so silly but its probably the most common thing thats wrong. Then if that is all gorrect disconnect the black/yellow (kill) wire on each switchbox and see if spark returns. Leave them off and just crank it for a spark check.

[rprinzo]

I know everyone is throwing out different ideas right now but PLEASE:
CHECK ALL THE WIRES ON THE SWITCHBOXES AND MAKE SURE THEY ARE ON THE CORRECT TERMINALS
It sounds so silly but its probably the most common thing thats wrong. Then if that is all gorrect disconnect the black/yellow (kill) wire on each switchbox and see if spark returns. Leave them off and just crank it for a spark check.

yup

[25two.stroke]

yup

Damn you know. And even I missed that one on yours! So easy to miss when two are swapped. It still all looks right but its not.

[mopractice]

Thanks everyone for the help,
I ordered new switch boxes. All the tests indicate that the trigger and stator are good. I also tried removing the bias wire and the black/yellow, still no spark

I also ohmed across the neutral switch and it reads 50 ohms - is that normal? I thought it would be just an open or closed switch