Iridium spark plugs

[captras]

Are Iridium plugs for our boats worth the extra cost? Do you have to change them out every year, or can you go longer in between changes? Recommendations?

 

[212s]

In my opinion, no they're not worth it. If your engine is designed for Iridiums, like many newer vehicle engines, then they will last a very long time. However, if the engine is not designed for them, using Iridiums is a waste of money as they will often foul due to heat range and fuel mixture. Just use the factory spec'd plug and change them every 100 hours and you should be fine. Stock plugs are not expensive and easy to change, and they're spec'd to work with your engines properly.

 

[tdonoughue]

Plus, even if your plugs last for 2000 hours, you should still change them every 1-2 years. Why? Because otherwise they can corrode into the block and cause real issues for you. I generally will change every year, but I have gone 2 years before. Now I stick with 1 year. Cheap insurance.

 

[212s]

Plus, even if your plugs last for 2000 hours, you should still change them every 1-2 years. Why? Because otherwise they can corrode into the block and cause real issues for you. I generally will change every year, but I have gone 2 years before. Now I stick with 1 year. Cheap insurance.

Good point...check every 100 hours or annually is what Yamaha calls for on the 1.8L engines. If I'm going to pull and check, I might as well change them.

 

[Canuckjetboater]

Plus, even if your plugs last for 2000 hours, you should still change them every 1-2 years. Why? Because otherwise they can corrode into the block and cause real issues for you. I generally will change every year, but I have gone 2 years before. Now I stick with 1 year. Cheap insurance.

What @tdonoughue says regarding change of plug intervals may be the best piece of advice you ever receive about your engines. These plugs protrude into the chamber and the thread tips can corrode if left in too long and result in plug breakage.

 

[drewkaree]

Plus, even if your plugs last for 2000 hours, you should still change them every 1-2 years. Why? Because otherwise they can corrode into the block and cause real issues for you. I generally will change every year, but I have gone 2 years before. Now I stick with 1 year. Cheap insurance.

This right here. I pull them every year to fog, so I figure why bother with the extra cost when I can put it towards the new set of plugs? It won't net me any extra speed or fuel economy as long as they are within spec, and I've seen the "plug corroded, can't remove" threads around here, so I view it as cheaper than inviting problems by leaving a "long life" plug in.

I have even considered leaving the plugs out over winter, putting the boots back in to cover the holes

 

[Augusto David Rodriguez]

did you guys know the gap measurements for 1.8 HO?

 

[AZMark]

did you guys know the gap measurements for 1.8 HO?

0.031-0.035