Head Gasket Leak?

[coyedsel]

My 75 HP Mariner was loseing some power. Started to install new plugs and found the bottom plug looked brand new. Put one of the old dirty plugs in and ran it about an hour. Pulled plug and it was clean as new. Does this indicate a blown head gasket or are there other posibilities?

 

[Faztbullet]

Re: Head Gasket Leak?

First the engine does not have a head gasket, a cleaned plug is a sign of water intrusion due to defective lower crankshaft seals or inner water jacket under exhaust plate .....

 

[coyedsel]

Re: Head Gasket Leak?

First the engine does not have a head gasket, a cleaned plug is a sign of water intrusion due to defective lower crankshaft seals or inner water jacket under exhaust plate .....

Thanks for information. Seems the engine needs a complete rebuild. Old engine and probably not worth it. Thanks again!!