1989 70hp spark plug or spark question

[partyhut]

I use my 70hp on a 28' pontoon and operate at 3500 rpm or less 75% of the time, WFO only when going for more beer. What spark plug would be best for this enviroment? Also how much gap should the spark jump on one of those adjustable glass tube checkers? I might have a weak spark on one or more coils. Thanks--BJ

 

[Elmer Fudge]

Re: 1989 70hp spark plug or spark question

It was my understanding that the 1989 70HP called for a surface gapped sparkplug like NGK-BUHW-2 or Champion L78V.

 

[partyhut]

Re: 1989 70hp spark plug or spark question

That is the plug that is in now. Could I go one heat range hotter without any damage and what would that number be?

 

[Vlad D Impeller]

Re: 1989 70hp spark plug or spark question

What is the plug that is in it now?<br /><br />You can also use Champion QL78V where radio frequency interference(RF) suppression is required.

 

[Bob H.]

Re: 1989 70hp spark plug or spark question

To my knowledge you're stuck with the NGK BUHW-2 or Champion L78V. These engines use surface gap plugs only for some reason. If the oil injection is hooked up and the plugs foul frequently look for weak spark. I search for different plugs for my 1987 80hp and surface gap was all that was offered even though there's plenty of clearance for a different style plug.