When you guys change spark plugs do you use the original plugs called for by the manufacturer or do you use some of the new super plugs with extra contact points that are supposed to burn better, last longer, and give better performance and mileage? Has anyone tried, platinum or iridium plugs in their outboard?

Has anyone tried, platinum or iridium plugs in their outboard?

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wont work.

A buddy of mine needed to change plugs in a 2009(Ithink) mercury 90 optimax since it was idling rough.

went down to the parts store and got plugs, installed them, it ran worse.

He took it to a boat mechanic and the mechanic popped off the cowling and in 10 secs said "there's your problem, you got the wrong plugs. You have to run merc plugs."

installed Merc plugs and it ran like a top!!!

Disclaimer before anyone bashes me...... in the older motors I THINK you can probably get away with it, but the newer motors you have to use manufacture spec'ed plugs.

You should use what is called for by your motor mfg. If in doubt, call them and ask what other plugs will work in your motor. Sometimes, especially with older motors, there is a new plug that will run better in the old motor and they will advise you to use it. 

My OEM plugs are NGK Iridium.