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A friend of mine blew his 225 EFI a few weeks back. Its a 1999 and he really uses it so as far as I am concerned its been good to him. The only problems up to two weeks ago was the lower unit seemed to find hard things in the water and you can't blame that on Mercury. This motor was USED and was hardly ever used at much less than full throttle.

I saw the motor and THE piston after it was torn down. The piston had a good sized hole in the top and that hole was for the most part square and dead center in the piston. I didn't really measure it but I am guessing I could have put perhaps my index finger in that hole if not my thumb.

What would cause that?

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Release the fighter! Gators rule the SEC!!!!! Seminoles ruled the ACC!!!!! (now past tense)

Without seeing it first hand my guess would be impact with the spark plug.

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I'm not fluent in Idiot could you please speak slowly?

Unless he had just put in new sparkplugs how could that happen? He and I had fished the previous weekend and it worked just fine....

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Release the fighter! Gators rule the SEC!!!!! Seminoles ruled the ACC!!!!! (now past tense)

Like I said with out seeing it I am only guessing. A rod bearing could have let go and caused it to make contact with the plug. Carbon on top of the piston could also cause this to happen. Any damage to the head? Wrong plugs installed? Usually when a piston gets a hole in the top of it, it is from impact or detonation from unburned fuel/carbon deposits.

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I'm not fluent in Idiot could you please speak slowly?

I will send this information to my friend... His idea is that the injector for that cylinder quit and that didn't make sense to me... this does.


Thank you very much.

c57

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Release the fighter! Gators rule the SEC!!!!! Seminoles ruled the ACC!!!!! (now past tense)