1987 50hp force spark plug question?

keepNitreel

Chief Petty Officer
Joined
Aug 21, 2008
Messages
446
Hello all, I have searched this great forum and found many threads with answers to almost all of my questions without having to post. But I have found nothing on my spark plug question. I recently (Sunday) picked up a 1987 50hp force model# 507X7B SN# 1285 and I notice that the spark plugs in them were L77JC4. From threads that I did read that contained Spark plug info the proper plugs for this motor is L82c or NGK B7HS. I was told that the engine has no spark (have read all treads regarding no spark) and both coils are cracked (also read threads on cracked coils) but it turns over. The motor was free so I don't mind shelling out $200 on new coils. So my question is, should I change to the proper spark plugs or stay with what was in the motor but buy new ones? Also what possible damage can or has resulted from the use of the L77JC4 plugs that are in there now?
 

Dave K.

Chief Petty Officer
Joined
Sep 21, 2007
Messages
437
Re: 1987 50hp force spark plug question?

my motor had regular tip plugs when i bought it. 85hp calls for a surface gap plug. alhough the performance was better w/ the tip, i found out they can burn a hole in the piston. since then i ONLY use what the motor calls for.
 

keepNitreel

Chief Petty Officer
Joined
Aug 21, 2008
Messages
446
Re: 1987 50hp force spark plug question?

my motor had regular tip plugs when i bought it. 85hp calls for a surface gap plug. alhough the performance was better w/ the tip, i found out they can burn a hole in the piston. since then i ONLY use what the motor calls for.
Thanks for your response. I think I will stick with what the motor calls for.
 
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