1978 Mercury 140hp Sparkplugs & tuneup?

[motoboatguy26]

Hi, Im doing a tuneup on an old 78' mercury 140hp that I just got. It's been sitting in a garage for about 5-6 years. I have a set of 6 new NGK buhxw-1 plugs that were laying around & im wondering if this is a good plug to use with this motor? Also just bought a water pump kit, fuel pump kit & three carb gasket kits, so I can clean the carbs. Anything else missing with my tuneup? The reason im doing the carb cleaning is because when I primed the bulb for the first time gas shot out of a upper hole on the middle carb, not 100% sure what that meant, but I think maybe the float was stuck? thanks

 

[Barnacle_Bill]

Re: 1978 Mercury 140hp Sparkplugs & tuneup?

You are off to a good start. Here is some pertinent reading for you.
http://forums.iboats.com/showthread.php?t=158086

 

[Chris1956]

Re: 1978 Mercury 140hp Sparkplugs & tuneup?

Clean the carbs. I think the plugs are BUHW. Do a link and synch, hit the zercs and change the gear oil. Check out the wiring. Those old wires lose insulation.