2010 90 Optimax 1b803508. How often should the spark plugs be changed? According to the service manual they should be inspected yearly and changed as needed. I have only put 32 hours on the ones that I put in at the beginning of the year and the ones I replaced were the 10 year old originals. I pulled them out and checked the gap, and they are all at .032". The picure below shows the 1 year old ones with 32 hours on the left and the Originals on the right.
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Once per year, or every 100 hours of operation, whichever occurs FIRST.
See: Recommended Annual Maintenance for Optimax Engines
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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Is there any reason for that? It seems excessive on a motor that doesn't have that many hours put on it.Originally Posted by EuropeanAM
Some of the reasons include potential for fouling/misfiring, plug degradation or porcelain failure (around electrode), and of course- the inconvenience of a trip to the water with an engine that won't make power due to something as simple as a fouled plug.
Doesn't mean that they "can't" run longer, just that it's recommended (for some good reasons).
Have to remember that the duty cycle is twice that of a 4-stroke engine, and often at pretty high RPM's for extended periods, too.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
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