Reply With QuoteI do not see a problem running it with the compression numbers.
115 Horse Mercury Serial 644XXXX with a jetdrive. Pulled the plugs to check and clean. Top five were good. Bottom plug was white, wet and oily.
Compression check:
#1 = 130
#2 = 130
#3 = 130
#4 = 130
#5 = 130
#6 = 150
Will it hurt to run like that? Had the drive off, water hose up the waterpump outlet and had water out the exhaust shower and tell tale before I ran it. This was all before I pulled the plugs.
Thanks in advance.
I do not see a problem running it with the compression numbers.
I'm no expert but that sounds like a water leak to me. Is the engine missing? Does it surge at WOT?
No. It was right where it's supposed to be.
Sorry, I had to do that.
Seriously, though. No surge at WOT. Idles a little rough, though.
Here's the last thing I did. Sprayed some carb cleaner in the spark plug hole. Spun the motor over with out plugs to blow out the oil/water/carb cleaner mix. Hooked the sparkplug wire to th plug to check for spark and spun again.
Put in all the plugs and connected all but the bottom one. Started it and ran a while. While it was running I hooked the bottom plug wire and it smoothed out.
I'm thinking it had been running on 5 holes for a while, maybe. Supposedly just before we bough it, Nov '03, the power head had been just rebuilt. If that's the case, it sure ran good for running on 5 out of 6.
Thanks for your response.
I assume that when you say "wet and oily" that would be wet with fuel?
Sounds like an ignition miss. A V6 will run pretty damn good down a cylinder. Swap the plugs around and see what happens. You might have a bad plug, wire, coil, etc.
CHANGE ALL 6 plugs...
If it's the same, I'd look at the coil.....
Boat Racer; 6 coils, spark @ #6. Thanks for your advice.
Forkin' Crazy; I probably should have explained better. Milky white/oily. My train of thought is that #6 never fired after the re-build and I just found out about it.
There is spark @ #6 and when idling w/#6 plug in and wire disconnected idle was still rough. Connecting #6 wire cleaned up the idle.
Thank you both for your ideas.
Gonna run it for a couple of hours and check the plugs to see if #6 is firing. If not, I guess it's time to change gaskets.
I'd think, if it was the gasket, that cylinder would be down on comp. & not up....
Does that cylinder have a sleeve & a newer looking piston?
Won't a bad exhaust divider gasket cause water to get into the cylinder?
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