Quick Spark Plug Question

[bds85466]

The shop manual for my 72 johnson 125 hp says to use a:

L76V* There's a note for the gap that says "Not Adjustable".

*Sustained low speed operation; Use L77J4 gapped at 0.040in

What does this mean? What spark plug replacement should I buy?

 

[tashasdaddy]

Re: Quick Spark Plug Question

if you do a lot of fast running use L76V, if you do a lot of slow running or trolling use the gapped plug L77J4, if you have a radio or fishfinder put a Q in front of the numbers, these stop interference from the motor.

 

[Joe Reeves]

Re: Quick Spark Plug Question

The 1972 125hp Evinrude/Johnson has what is called Battery Capacitance Diischarge ignitionx, whereas a internal rotor and distributor cap are incorporated under the flywheel. This ignition has gaps to jump within that system.

Due to the extra gap to jump, set the spark plug gap to .030 on the L77JC4 or QL77JC4 Champion spark plugs.