MNbowrider72
New Member
- Apr 7, 2019
- 27
- Boat Info
- 1994 180 BR Signature
- Engines
- 5.0 Mercruiser w/Alpha One Drive
Yesterday, I just finished replacing the fuel/water separator on my Merc 5.0 Alpha One ('94 180BR Signature). A previous owner had upgraded from a 4.3 and it's a tight fit. The separator seemed to solve 90% of the fuel delivery issue, as I just had it out on the water this afternoon and was achieving mid 40s mph top speed when previously it was only mid-30's with occasional spikes into the 40's and frequent bogging.
Feeling victorious, I was lapping the lake at full throttle when I hard a fairly loud "pop". I slowed to an idle and looked inside while my son idled back to the dock, as we were close. Upon further inspection, I could only tell that a spark plug wire had fallen off. I did not notice any loud internal noise that would indicate a thrown rod, or something catastrophic, only a loud engine. It seems that the core of the plug shot out, or was knocked off, with some force, and that the sound was air escaping the cylinder. The motor is fairly new, oil clean/full and maintained pressure. To add to the mystery, I found a seemingly unrelated nut, and hose clamp in the bilge -as seen in the attached pic. I had cleaned the bilge spotless when I did the fuel/water separator yesterday, so I know they weren't there before. The plug location is very sheltered and not near any moving things that could knock it off.
I am at a loss, and of course it started to rain while I was diagnosing... so here I am online. Any ideas where to start??
Feeling victorious, I was lapping the lake at full throttle when I hard a fairly loud "pop". I slowed to an idle and looked inside while my son idled back to the dock, as we were close. Upon further inspection, I could only tell that a spark plug wire had fallen off. I did not notice any loud internal noise that would indicate a thrown rod, or something catastrophic, only a loud engine. It seems that the core of the plug shot out, or was knocked off, with some force, and that the sound was air escaping the cylinder. The motor is fairly new, oil clean/full and maintained pressure. To add to the mystery, I found a seemingly unrelated nut, and hose clamp in the bilge -as seen in the attached pic. I had cleaned the bilge spotless when I did the fuel/water separator yesterday, so I know they weren't there before. The plug location is very sheltered and not near any moving things that could knock it off.
I am at a loss, and of course it started to rain while I was diagnosing... so here I am online. Any ideas where to start??