S/N:0G825341
1999 Mercury XR6 (carb)
Oil Injection Deleted/Premix 50:1
This past Sunday evening i was heading back to the ramp and on the last stretch i did a short WOT pull as i do at the end of most fishing trips. Just as i was approaching 5400rpms i experienced a sudden loss of power paired with a terrible rattle coming from engine. I knew right away what happened. i limped to the ramp, winched my boat onto the trailer, and pulled the plugs when i got home. Just as i had feared, the plug from the #5 cylinder had metal shavings on the electrode. Oh, no. Monday after work i went and pulled the head off the afflicted bank of cylinders to have a better idea of the damage, and i've attached pictures of what i found.
Has anyone seen a damaged piston of this nature? Im not sure what could have caused this or what i should do from here. At the time of power loss i had over 15psi water pressure and the head gasket didn't appear to be blown. Am i looking at the result of pre-ignition? Im left at a fork in the road between rebuilding or repowering. This motor has been bullet proof up until now. I apologize for all the questions, but im just left here scratching my head.