1987 johnson 175 spark plug recomendation

[jpwalsh]

Hi guys, i picked up a boat with a 87 175 johnson, it runs great, but i was going to replace plugs , and i noticed it has NGK B7HS 10 plugs and west marines book had a whole different number for it. I would like to put in the correct ones, and hopefully these havent effected anything. also what is the recommended gap, thanks

 

[ezeke]

Re: 1987 johnson 175 spark plug recomendation

Use the Champion plugs in this chart: http://www.boatsetup.com/SparkPlugChart.pdf

 

[jpwalsh]

Re: 1987 johnson 175 spark plug recomendation

it recommends the champion ul77v, is the gap .030 like the others? it isnt listed

 

[ezeke]

Re: 1987 johnson 175 spark plug recomendation

There are no gaps on the Champion plugs with a V in the number. Surface gap plugs were used to prevent pre-ignition in certain CD Ignition systems.

 

[jpwalsh]

Re: 1987 johnson 175 spark plug recomendation

thanks for your help

 

[throwback2332]

Re: 1987 johnson 175 spark plug recomendation

OMC recommends the use of Champion QL77JC4 or L77JC4 plugs gapped to 0.040in. prior to '89. High speed use OMC recommends Champion QUL77V or UL77V non-adjustable gap.

Champion NGK AC Motorcraft Autolite
UL77V BUHXW-1 VB40FFM AVZKO 2892
L77J4 B9HS10 M40FFX AV901X-4 2634