PLEASE HELP 95'-96' 3.0L 225 EFI 328hrs 1 owner no spark 1 cyl

[DevonArden]

<0G274005>

Hello there my name is Devon and well I have read your forums for long enough its time to join in!

i just had a 93' 200 2.5L pop on me so the hunt was on for new power..

i happened to find a 1995-1996 3.0L 225 EFI in UNBELIEVABLE condition i mean im putting finger prints on it while working on it..1 owner 328 hours total time .. over serviced motor...he was 91 years old WWII pilot he owned and started up multiple airways serviced and sold hercules air planes to military so this motor was very well taken care of ...long story short ...he passed away and the family sold it to me for 2500 bucks i have all the records for services done as it was the same shop he bought it from and that i picked it up from.

i brought it home...hooked up everything and it fired right up ...sounds amazing beautiful idle immediatly ..im happy

so we install on the boat..take it to the water and head on out the no wake zone... i slowly start to roll on the throttle and she starts coming alive ...but stops at 3000 rpm is a dog trying to get out of the hole...so we back off..check the throttle linkages make sure im getting full range out of the throttle ..made a adjustment and now achieve full throttle (things just havnt moved in a while and need shot of WD40) i then rolled on the throttle and it was a little better to the point i can now get on plane but still seemed underpowered..once on plane i trimmed out a little adn all the sudden she comes alive and starts flying ....back off ...roll the throttle ..shes slow out the hole once on plane you can hear motor wake right up and boom to the moon we go. ..seems like a cyl is coming to life once we are on plane . so we went back to dock and i spent the day givin it some love and cleaning and lube ...

while im doing so i notice the heat from all the warm cyl but no heat from one in particular ...the top hole on port side was cold, so i grabbed my inline spark tester with the light in middle and tested all other 5 holes leaving the cold one for last ...and sure enough the top hole on port side was showing no spark ..i figured maybe its the coil from sitting for a few years .. so i swapped the coil, plug wire, and spark plug with the sister cyl and it fired just fine when plugged into its sister cyl and its harness and now when i swapped the coils the top hole is still no spark even tho it has the good working coil from sister cyl ... so the problem stays on the one hole no matter what coil i put to it ...that hole has no spark


i chased back from the clip plug on the coil down the harness to the next plug then unwrapped a bunch of the black tape and casing looking for broken or corroded wire ..and everything is encased in its factory dielectric grease and looks brand new

i am used to the carb and power pack 2.5L i can multi meter the hell out of them isolate the problem part ...but this EFI AND computermatronics are makin a guy nervous ...

are the ignition ecu the equivalent to the powerpacks?

and what other then coil could be causing just the one cyl to not spark? is it possible i have a bad ecu? or maybe a wire from battery made contact where it shouldnt and burned up the ecu?

its just absolutely immaculate and want to get it right

HELP ME! thanks in advance


serial # - 0G274005
1995-96
225 EFI 2 stroke
22.5 foot seapro 220WA

[JOE54]

dout ECU test stator , get a manual ,swap firing cdm for one not firing see if no fire follows swap

[DevonArden]

dout ECU test stator , get a manual ,swap firing cdm for one not firing see if no fire follows swap

I've got a seloc manual for these motors..and it guided me through the full electronics and ignition testing for my 200 2.5
This should have the numbers for this motor as well ...but I did already swap the cdi ignition coil from dead hole with another hole ..and the coil then fired on the other hole ..and the coil that WAS firing once put onto the trouble hole it now doesn't fire ..so it's staying isolated to one hole no matter what coil goes to it ..which makes me think my next step would be power pack ..but I believe a power pack doesn't exist on these efi motors ..its now the ecu brain computer

[JOE54]

test the stator

[DevonArden]

Gonna have to pull the fly wheel todY and have a look ...took a good look at it yesterday while flywheel was on ...it looks Shiney new ..no melting no discoloration..will still take a good look

[DevonArden]

Is there a specific coil I should be looking at? Any other Time I have had to do a stator ..it was obvious..effected many cyl ..surged in power...felt like limp mode ..was discolored...leaked gross stuff....I believe I'm gonna look at it and its gonna be mint looking..and testing ohm resistance doesn't always show the problem...whats the sure way of testing the stator to see if it's bad....can itest the output to the capacitors?

[EuropeanAM]

You do not need to pull the flywheel to TEST the stator.

Forget the Seloc manual. Use an OEM Mercury Manual, specific to YOUR engine's displacement and serial number range.

This engine has six individual ignition windings in the stator. VERY simple to check: Unplug stator connector, check resistance between each green wire and GROUND (earlier stator had an individual ground wire for each winding, later stators joined all the white grounds to a bolt on the block).

Resistance should be virtually identical for EACH of the green wires. If you have one that is significantly different, you need a STATOR.

[DevonArden]

Thanks for thr replies everyone....so green to white wire ...or green wire to any ground such as the block ?

[EuropeanAM]

EACH green (there are six different green wires in the stator harness, differentiated with stripe colors).

[DevonArden]

Do I check them to any ground such as the block? Or to each white wire

[EuropeanAM]

It will be very obvious when you unplug the stator wiring connector what you are checking to.

You either have six white wires stacked on one bolt, or a connector with 12 wire in it (versus six like the later ones had). The earlier stator was only used for approximately 1.5 hrs (max).

[DevonArden]

I hate to be so ignorant ...but I get checking each of the 6 green to ground ...but what I'm not getting ..no matter what one I have early or late ...check green wires to any ground that's reachable....or do only use the white wires or stack of white wires to a bolt ....


Green to block ground ...or green to white wire ground ...not sure if it will make a difference
Again I apologize for not getting that part

[DevonArden]

Am I checking to the white wires as my ground or to any source of ground I can reach

[EuropeanAM]

Devon: You are literally going to have a plug directly next to the six (6) white wires, which are attached to a single grounding bolt.

Check to THAT GROUND BOLT, reading resistance (in ohms) between each of the green wires in the plug to that ground bolt.

All readings are with the stator connector UNPLUGGED.

Don't over think it... it's really simple.

[DevonArden]

Lol yes sir ...new motor ...perfect condition ...only money I had ...wanted to make sure I'm not ruining anything ..as stated I'm new to the computerized units .. was unsure if I was to check every green with its own white ...thank you Don

[DevonArden]

Is it true though however that even a good ohm reading on all 6 it does not indicate that your stator is OK? Something could still be wrong with it correct

[DevonArden]

Cuz if it's not the stator ..am I correct that the next goto is the ecu?

[EuropeanAM]

Is it true though however that even a good ohm reading on all 6 it does not indicate that your stator is OK? Something could still be wrong with it correct

True, but very rare. Most commonly loss of spark on ONE cylinder with this model is either the CDM or the Stator. Very rarely (but possible) to be the ignition ECM or the wiring harness.

[DevonArden]

I have one concern ...when we put power to the motor ...we did what was always the common practice and we put the red 12v positive to the starter solenoid and we put the negative ground from battery to the ground location on the starter ...gave the key a turn and it didn't turn over ..just the starter motor spun very slow as if you were hand turning it ...

Then realized that the ground on this motor goes to the side of the plate that holds the trim solenoids and starter solenoid...put it there and then she fired right up ...any chance we messed something up in ecu that way ?

[DevonArden]

resistance checked the stator and found one of the leads reads OL. for overload meaning its got a broken circuit for that cyl!! thanks a ton for the info from all involved .. now to find somewhere selling a stator for a decent price in canada