Spark Plugs

[steve waters]

How often do you change your plugs in your inboard engine?
I have 300 hours on mine.

[Bob H.]

The problem isn't so much the hours but corrosion. I used to do my cruiser every year, but mine had easy access. I did my wires every 5 years, that's about the breakdown point for the insulation. I'd rather replace them then wait for them to start arching in an enclosed engine compartment.

[cris4tuna]

My Yamahas 4 stroke call for every 100 Hrs of use. I here that if you do not change them in time they somehow pit your pistons and cause premature engine failure?

I don’t not know if that is true I only know that the Yamaha manual calls for every 100 Hrs...

Good luck..

[Harry]

I replace them on my 302 I.B. every Spring after running the fogging out of the engine. Usually average 200 hours for the season. I agree about 5-yrs on the cables.