9.9 Evinrude fouling plugs

[Mark Fergo]

I have a 1993 9.9 evinrude on a 16' Bass Buggy that is fouling plugs (heavy black deposits) with less than two hours running time. Motor surges then quits & woln't start without new plugs Any ideas anyone?

 

[ob]

Re: 9.9 Evinrude fouling plugs

What plugs are you running and what pitch prop are you pushing the boat with?Too steep a pitch can cause the cylinders to load up as the engine is being lugged.Also a plug other than the recommended Champion can cause ignition issues.