Weak Spark

[Themanofsteel]

I have a 1982 Mercury V6 150hp outboard. Cylinder 2 is getting a weak spark. As a result I’ll not getting full power. All the other sparks are perfect. I recently replaced...
• The spark wires (And I swapped wires to test them)
• The spark packs (The thing the sparks wires attach to )
• The Stator and Trigger
• CDI Switch Boxes
• The rectifier
Any ideas?

 

[racerone]

Not sure what " weak spark " is here.------Put a number to it.-----Does spark jump a gap of 7/16" on all leads , yes or no ?

 

[Themanofsteel]

Not sure what " weak spark " is here.------Put a number to it.-----Does spark jump a gap of 7/16" on all leads , yes or no ?

See the attached pics. All the sparks are bright red, only one is weak or faint red.

 

[Chris1956]

Well, after all the things you replaced, you might double check the wiring between the stator and trigger and the Switchboxes (CDI units) as well as switchbox to the coils (spark packs). Also check all the ground wires and wipe the seat of the spark plugs to make sure they ground well.

 

[racerone]

??----But does the " weak " spark jump a gap of 7/16" , yes or no ?.-----What other trouble shooting has been done ?

 

[Themanofsteel]

??----But does the " weak " spark jump a gap of 7/16" , yes or no ?.-----What other trouble shooting has been done ?

I haven't done any other trouble shooting and I did try to jump the gap.

 

[racerone]

If the spark can jump a gap of 7/16" it has plenty of voltage.------Perhaps your trouble is elsewhere.-------Did the lack of power show up suddenly ?----Developed over time ?-----Trouble shooting is the path forward.-----Could also be an issue with the boat too.

 

[Themanofsteel]

If the spark can jump a gap of 7/16" it has plenty of voltage.------Perhaps your trouble is elsewhere.-------Did the lack of power show up suddenly ?----Developed over time ?-----Trouble shooting is the path forward.-----Could also be an issue with the boat too.

Seemed to show up suddenly. It was getting full power, then I had not taken the boat out for a couple of months. When I took it out the last 2 weekends i noticed it under performing.

The RPM’s don’t go past 4000. I use to get it up to 5000+ when I hit full throttle.

 

[racerone]

Can you answer with a yes or no on that spark jumping a gap of 7/16" ---Trouble shooting means gathering the facts on motor issues.-----Could be a plugged carburetor ?----Water in the fuel ?----Post your actual compression numbers taken now.----Perhaps run with a timing light on all cylinders to see how spark behaves.-----Make sure all carburetor main jets are clean before launching the boat again.

 

[Themanofsteel]

I meant to say I did NOT test the gap jump.

 

[racerone]

Oh well,----- good luck with your trouble shooting.

 

[Themanofsteel]

Yeah. Got some testing to do. Ok