My first spark plug change did I make a mistake?

[ADoyle3]

Can't resist my two cents... The plug is made of steel and is being threaded into an aluminum cylinder head...You will NEVER break the plug..You may strip the threads in the head (bad news) From what you described you have broken neither. Most spark plugs are recommended for 100,000 mile in automobiles (that's a LONG time). I would guess 2-3 yrs or more in a properly running boat would be fine.. Years back I had a R1 motorcycle new (similar inline 4 Japanese engine) after 4 years I changed plugs and they looked new. If you don't have a feel for the wrench sometimes not touching things is best. Same with bringing it to the boat yard for service.. I wouldn't trust some of the kids they hire to put air in my Air Head tube....Those plugs you pulled would have gone for years...No carbon build up, no expansion of gap..Clean running motor.

 

[I_squared_r]

I am a former auto mechanic, powersports hobbyist, and engineer. I always install spark plugs to
18ft lbs, but I have this down to a feel without using a torque wrench. I never used anti-sieze because the boots don't allow moisture. Ensure that the boots are clean, apply dielectric grease to the mating surfaces, and install. You can pull the plugs at the end of the year for inspection. I like to find potential issues before storage