3.0 High Speed Miss

djpeters

Lieutenant Commander
Joined
Jun 9, 2010
Messages
1,824
I got a high speed miss. Pulled the spark plugs. This is #1...


#2 has a slight amount of the same.

#3 & #4 look normal.

Do I have a bad head gasket?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,226
looks like oil fouling.

could be rings, could be head gasket, could be valve seals. time for a round of compression and leak down testing
 

djpeters

Lieutenant Commander
Joined
Jun 9, 2010
Messages
1,824
looks like oil fouling.

could be rings, could be head gasket, could be valve seals. time for a round of compression and leak down testing

I pulled the distributor cap off and the contacts have deposits on them and the rotor is dirty also. I had oil spewing all over the motor last week from a cracked oil filter and there's a film inside the cap. Going to run and get new plugs, cap and rotor. While I'm at it I want to check the timing. I know I need the shunt and have read the procedure. Where would I find the timing spec? Motor is an OMC Cobra 3.0 GS Model #302CPHUB, it's in a 1995 FourWinns Freedom 170. Thanks,
 
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