How to find proper Gap for spark plugs on '87 Mariner 175HP

[apaseman]

I have a service manual, but it doesn't tell me what the gap should be for my spark plugs on my '87 175HP Mariner Outboard. I've tried numerous google searches as well. Any ideas?

 

[dwco5051]

Re: How to find proper Gap for spark plugs on '87 Mariner 175HP

It has been a while but I seem to remember using surface discharge plugs in these motors. Check the plug number on any of the plug cross-references and see if that is so. Surface discharge plugs have a fixed gap by design that is not adjustable.

 

[Dukedog]

Re: How to find proper Gap for spark plugs on '87 Mariner 175HP

I have a service manual, but it doesn't tell me what the gap should be for my spark plugs on my '87 175HP Mariner Outboard. I've tried numerous google searches as well. Any ideas?

Supposed ta run NGK BU8H. No gap needed!