mechanic tells me head gasket is blown

[whosurpopi]

I have an 02 four stroke 140 that started running rough last week. I changed the plugs, and checked compression and found the bottom one to be 90psi. I had a mechanic come out today and test it, and determined the head gasket is bad. The bottom cylinder is filling up with water, and when he sprayed oil in it, the psi increased for a little. How bad is this, and could anything else cause the water and loss of compression besides the head gasket before I put in a lot of money in this? Thank you.

[whosurpopi]

I was just told it could also be an adapter plate. Does that sound right?

[mitch]

yes that sounds right but you will still have to dismantle to find out where the corrosion is and water ingress is occuring

they have problems with engine holder corroding

[whosurpopi]

its apart and the head had corroded

The head is missing a small chunk at the bottom cylinder. The mechanic says the motor is not turning over as easy as it should, and that means i should replace the rings and have the bottom cylinder rehonned. What do you think?

[mitch]

you will have to weigh up what the costs are v new motor ?

how many hours have you done ?

[whosurpopi]

the motor has less than 100 hours, but apparently when I bought it, it hasnt been properly flushed.

[whosurpopi]

The mechanic is saying to rebuild that is more than 4k. I found an 08 150 horse for 3500, what should i pay for installation?

[mitch]

well depends on your skill level and determination you could buy a cheap engine lifter and do it your self .. as all you are changing is the engine ?

a 150 is a much better motor than the 140.