25hp four stroke- electrical mystery!..please help.

[mintcoine]

I have a 25hp 4 stroke Yamaha unit with high thrust prop and lower unit that powers my 30 foot work boat.
Engine was running fine but it just quit..thought the dead mans handle had been pulled out but wasn't that.
Removed plugs and they were wet with gasoline, indication that its an electrical problem. checked for spark after cleaning plugs and turned engine over with plugs grounded against clean metal on side of cylinder head but no spark...not even a weak one! I changed plugs and fitted a spare coil and still no spark. Unplugged the workboat wiring harness and plugged in the harness used on my 50 Yamaha runabout and turned the 25 over fast but its still not firing.
I'm figuring its something under the flywheel in the magneto? . am i on the right track or have i missed something? any help appreciated.
I live in a remote part of the Bahamas with no agency nearby. Although I'm not a trained mechanic, i have been doing repairs ans servicing all my own engines for 30 years....this problem has got me.

thanks Bob

[rodbolt17]

could be a bad pulser coil, bad charge coil,bad ign coil,failed CDI or a shorted stop switch.
first is to unplug the white wire at the CDI and retest.
if still no spark you will need a DVM with a DVA.
a model number would help as not all F/T25 yamahas were built with the same ign. some used mercurys Motorola ign system as they were built by mercury marine and painted Yamaha silver blue.

[mintcoine]

F25A Yamaha electrical problem....

thanks so much for coming back with guidance. I have three other T25 engines from 1999 to 2003 and i,ll try swapping a few more parts in hope something will spark!...all post again soon. Bob

[rodbolt17]

logical testing is FAR faster and WAY cheaper than random parts chunking.
if something CAUSED a failure of a part you may end up with more bad parts.
your parts your money, do as you wish.