Logo
FULL SITE MENU

Compression on Mercruiser 1979 120

R

roadpacker

New member
I have a Mercruiser 120 4 cylinder engine out of a 1979 Galaxy that has very low compression on two cylinders.The readings on # 3 and 4 are a strong 150 while on # 1 and 2 a very poor 30.This engine has not been started in five years and the oil is a milky color.I am thinking it has a blown head gasket,but this is just an uneducated guess on my part.A head gasket replacement is within my skill level,but before I do it,I would like to hear what the pros think could be wrong.Thanks in advance for any advice.
 
Re: Compression on Mercruiser 120

Could be a head gasket and could be a cracked block, or a cracked water jacket into a cylinder.

So when you pull the head you will know more.

Good news is if the mani and such is still good all you will need is a new block.

Is this boat worth the time and money, and sweat and tears to get on the water?
 
Re: Compression on Mercruiser 120

Thanks Chief, for the reply to my question on the compression problem.And thanks for pointing out to me the problems that I may face in repairing a bad motor to go in a POS boat that may never see the water again.You just gave me a reality check that probably will keep me from throwing good money after bad.Thanks again.
 
Re: Compression on Mercruiser 120

I am truly sorry, but i wanted you to know it might not be worth your time. I sunk money into a boat i can never sell, and if i had to do over maybe i wouldn't have done it.

I wish you luck in all of your future endeavors !
 
Back
Top