1988 Force 125hp Spark Plug Gap?

[richb420]

Hello everyone, I have just purchased my first 1988 Bayliner Cobra boat with the Force 125hp engine and was wondering what the gap on the spark plugs is supposed to be. I just purchased the same spark plug (Champion L77JC4) that I had in the engine at Kragen but they are not sure if they are pre gaped. So, if anyone knows what the gap is supposed to be, please inform me. Also, this may sound stupid but where is the thermostat located on this engine? I want to check and clean it. Thanks for all the help! <br />Rich

 

[Realgun]

Re: 1988 Force 125hp Spark Plug Gap?

Welcome to iBoats RichsBayliner!!!<br /><br />Dont know the gap sorry the plugs I use are surface gap. the electrode is in the middle of a flat ceramic piece and the spark jumps across the surface. The thermostat is high up on the rear of the motor usually small and square. I believe there are 4 screws. Be carful removing the screws you may need penetrating oil and or heat to get them out. You will really want to replace the gasket if you take off the thermostat housing.<br />Better yet just get a new thermostat too.<br /><br />My next thing is to get a manual for that motor as there are a few things we cannot expain here but if you had the manual we could clear that up a bit.

 

[roscoe]

Re: 1988 Force 125hp Spark Plug Gap?

NGK sparkplug BUHX surface gap plug.<br /><br /> http://www.sparkplugs.com/more_info.asp?otherMotiveID=23418&pid=2623 <br /><br />Why surface gap plugs?:<br /><br />Surface and semi-surface discharge firing tips are less sensitive to voltage requirement increases due to gap growth(wear). Note the concave cut on the ground electrodes for even Gap growth (wear). In addition, this type of construction aids in burning away the carbon which can act as a bridge between the center electrode and plug shell. This bridging can cause plug misfire.