How bad is this gonna be?

[Stranger]

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.

 

[Scot]

Numbers look god. May be a bad plug or wire.

 

[cartman]

numbers look good #6 is a little more do to carbon build up keep good plugs in it and take it out and run it hard to clean out the engine

 

[Stranger]

Cartman: Apparently, before we bought the boat, the powerhead was re-built. I'm thinking assembly lube leaked down to the #6 cylinder and fouled the plug. Ran the motor with the top 5 plugs connected, connected #6 and idle cleaned up. thinking that #6 had been fouled for a while and now, well, it ought run better than great. Ran real good on 5.



Thanks for your advise and responses.

 

[thejeepdude]

Have you tried running some seafoam through it? That should clean it out if it is indeed carbon build-up. seafoam

 

[CChase]

Originally posted by thejeepdude

Have you tried running some seafoam through it? That should clean it out if it is indeed carbon build-up. seafoam

Ditto. Seafoam is good stuff. I'd run it pretty heavy into the intake, then dump what's left in the gas can. It will clean out just about anything.

 

[Stranger]

Seafoam?

Where can I get it?



I guess I should've explained it better. #6 was pumping milky white/oily gunk. Again, thinking it neve really fired from re-build.



Thanks, again for your responses and advice.