250 EFI Spark issues

I have a 2000 Mercury 250 EFI serial number 0T090962 and am having spark issues.

Last weekend the wife and I were cruisin about 25kts and ....boooog motor died, tried to fire it up, nothing, checked spark nothing, got towed in and started assessing the situation over the past week. Replaced the crank position sensor, replaced the stator... basically threw a bunch of money at the motor and still no evail. I did, however notice when I swapped the negative battery cables (same terminal on battery just moved the bottom to the top and so forth, had the negative cable running to the motor and one running to the other battery, just swapped their position on the terminal) I noticed when I did this starter clicked, switched em back and motor spun but still no fire?? Could I just have thrown about 300$ at a battery cable issue:facepalm:? I'm reeaalllyy hoping it's not a bad ECU.

Motor has about 40 hrs on a rebuilt power head

Any help is much appreciated

Re: 250 EFI Spark issues

Additional info I do have a pig tail to by pass the electrical system on the boat, I'm pretty sure the issue lies in the motor.

Re: 250 EFI Spark issues

"KISS" Keep It Simple Stupid
"Try before you pry"
"Uphill upwind"

Had some bad battery cables :facepalm: replaced the cables and motor fired right up. If you ever experience dead spark plugs, PLEASE PLEASE PLEASE check your battery cables, any green or corrosion, cracked or frayed copper, get rid of em. Or you can spend about 3-400$ at what you think is the problem and not fix it and realize your cables were shot. Yes new cables are expensive, however I got some Yami cables for free ninety free. Friends in low places...

Tight lines