Correct Spark Plug for '82, 25 hp Merc???

b22smith

Seaman Apprentice
Joined
Jan 19, 2004
Messages
32
I have bought a used 1982, 25 hp Mercury outboard and I want to make sure I'm using the right plugs. What brand of Champion or NGK plug is specified and the gap?
 

dilligafda

Petty Officer 1st Class
Joined
May 13, 2003
Messages
315
Re: Correct Spark Plug for '82, 25 hp Merc???

NGK B9HS-10 is the plug I would recommend and the gap is .040.
 

Redonthehead

Recruit
Joined
Jan 20, 2004
Messages
4
Re: Correct Spark Plug for '82, 25 hp Merc???

maybe they changed, but my '85 model uses a surface (fixed) gap plug.
 

dilligafda

Petty Officer 1st Class
Joined
May 13, 2003
Messages
315
Re: Correct Spark Plug for '82, 25 hp Merc???

Yup, the Merc recommendation changed. It was a Champion L77J4 and changed up to the NGK number.
 
Top