1986 Mercury 25XD

[Colton1012]

Currently fighting my Cougar Cub with a 25xd merc, having an issue with only getting spark on 1 cylinder and no fuel getting to carb. Will start and run on 1 cylinder while I spray gas directly into the carb. Really just need help finding the fuel pump/carb rebuild kit and what wires to ohm out to point towards bad coils, stator, switchpack etc. Seems almost impossible to find manuals/videos on these older motors.

 

[flyingscott]

What is your compression? Spark jump a 1/2" gap? Carb kit is

1395-9761 1 manual should be available call a dealer.​

 

[jimmbo]

Welcome to iboats

First things first. What are the Compression Numbers?
Perhaps the Plug Wire is no Good? You can swap the Wires to see if the spark moves to the other Cylinder
Is the Coil Cracked? You can swap the Coils to see if the No Spark moves to the other Cylinder.
If not then you check the wires going to the Coil from the Switch Box #17 or #18(two different ones were used) again you can swap the Wires for the coils.
After that the Stator and Trigger are all that remain

 

[Colton1012]

What is your compression? Spark jump a 1/2" gap? Carb kit is

1395-9761 1 manual should be available call a dealer.​

Compression was in the 110 range across both cylinders, and yes I could see spark jump.

 

[Colton1012]

Welcome to iboats

First things first. What are the Compression Numbers?
Perhaps the Plug Wire is no Good? You can swap the Wires to see if the spark moves to the other Cylinder
Is the Coil Cracked? You can swap the Coils to see if the No Spark moves to the other Cylinder.
If not then you check the wires going to the Coil from the Switch Box #17 or #18(two different ones were used) again you can swap the Wires for the coils.
After that the Stator and Trigger are all that remain
View attachment 387987

Compression was right around 110 across both cylinders, I have new wires and coils coming tomorrow that I will put on and double check.

 

[Colton1012]

As an update, new coils and spark plug wires till only have spark on bottom cylinder. When i swap the green wire on top of coils I lose spark completely.

 

[flyingscott]

How are you testing spark? It should jump a 7/16 air gap easily. Get the manual and start testing. The parts cannon gets expensive. I would guess your problem is in the switch box.

 

[Colton1012]

How are you testing spark? It should jump a 7/16 air gap easily. Get the manual and start testing. The parts cannon gets expensive. I would guess your problem is in the switch box.

I am testing with a spark tester. From my reading that is what I have came down to… but several people are saying I have a circuit interruption somewhere between battery and the coils.

 

[racerone]

But 12 volts from the battery is not used to make the spark.

 

[Colton1012]

But 12 volts from the battery is not used to make the spark.

Correct, a few have said to take a jumper wire from battery to the positive side of coil… but didnt make much sense to me. I ordered a new cdi/switch box that’ll arrive tomorrow so we will see

 

[flyingscott]

Correct, a few have said to take a jumper wire from battery to the positive side of coil… but didnt make much sense to me. I ordered a new cdi/switch box that’ll arrive tomorrow so we will see

The manual would have been cheaper. The proper tests would have saved you money. But you keep loading that parts Cannon.

 

[Colton1012]

Got it fired off but another issue arose, go to start with the key and solenoid just clicks. Both battery and solenoid drop from 12v to 1v when key is turned to crank.

 

[racerone]

Check battery cables.----Have battery load tested.

 

[Colton1012]

Check battery cables.----Have battery load tested.

Load tested bad, grabbing a nee battery and solenoid on my way home tomorrow morning. Would like it all to be new just for peace and mind.