Pontoon Boat & Deck Boat Forum

Went to change the plugs on my 2004 60hp Merc 4 stroke and was lost. The plug is incased in a plastic housing and I pulled the wire and can't figure out how to take the plug out. Do I have to take off the whole plastic enclosure....jeez, I thought I was smarter than this! Thanks guys.

That may be the coil pack that you have to remove to get to the plug hole. Usually it is just one bolt and then you can access the plug with a socket extension. Not sure with the Merc (Yamaha) if that year uses distributor-less ignition (coil packs).

Hopefully someone with more knowledge on that year will chime in shortly.

I had a 90 04 and to get to plugs you removed the plastic housing in back of motor. It had 5 or 6 bolts I believe. Pull it all the way off and remove plug wires. Be aware they prob stuck to plug and will tear when you jerk them off. I put some lithium grease in them when I put them back on the new plugs.

lakerunner wrote:I had a 90 04 and to get to plugs you removed the plastic housing in back of motor. It had 5 or 6 bolts I believe. Pull it all the way off and remove plug wires. Be aware they prob stuck to plug and will tear when you jerk them off. I put some lithium grease in them when I put them back on the new plugs.

I would use di-electric grease. Not sure if lithium will conduct electricity and it would be a pain to get out of a plug cap if it doesn't

All the above plus I would buy a pair of plug wire boot pliers! They allow you to twist and then pull the plug boot up and out with out ripping it up. They work great and should be available at a auto parts store. I've had mine for so many years I can't remember where I got them, but worth way more than they cost in saved spark plug wires.