1994 Johnson 30 hp 2-stroke / 2 cylinder spark plugs

Bannister 6905

Petty Officer 2nd Class
Joined
Jun 5, 2015
Messages
110
Struggling with replacing the plugs on my 1994 Johnson 30 hp 2-stroke.
I am finding conflicting info as far as correct plug to use (I prefer NGK), plug gap and compatibility with the ignition system.
BZ7HS-10 is currently in the motor, gapped at 0.030"
NGK advises against using "R" plugs, as they may cause problems with the ignition. They call for the "Z" - inductive resistor type - for CDI applications.
Who knows the correct plug to use, what gap?
Thanks in advance.
Bannister
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,151
Champion Ql77jc4 gap is .030. Use champions in an OMC motor they tend to work better than NGKs.
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,469
Your current NGK's are the correct cross-over and will work fine, so keep 'me for spares..
 
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