Compression Problems with 1999 Mercury 150HP Bluewater Series

[tarheelborn66]

I am looking at purchasing this boat and just had the engine checked. The compression is as follows: (these are as you are standing behind the engine) Top right - 127, center right - 0, bottom right - 127, top left - 125, center left - 124, bottom left - 100.<br /><br />When I test drove the boat, the engine would not climb above 4000 rpm at WOT. also, would not idle that well. It would cut off sometimes and you would have to pump the bulb. The boat has sat in dry storage for a year and when I took it out last week, it was the first time it had been run in a year. Right before it was put in storage, it had been tuned up and the carbs were cleaned.<br /><br />Without ever having seeing the engine, what could be some of the things that could cause this cylinder to have a 0 compression? Could the reed valve be stuck open and that cause the 0 compression?<br /><br />The engine runs fine other than it won't go over 4000 rpms.

 

[Barnacle_Bill]

Re: Compression Problems with 1999 Mercury 150HP Bluewater Series

To have 0 compression there has to be something major wrong and its not a reed. You might try pulling that plug and see if you can see anything with a flashlight. Like a hole in the piston. You may have to pull the head to see the whole story.

 

[joblo33]

Re: Compression Problems with 1999 Mercury 150HP Bluewater Series

I'd say start looking for a different boat unless this one's really cheap. It'll definately need some major rebuild work if not a new powerhead.<br />Eric

 

[Coolmaker]

Re: Compression Problems with 1999 Mercury 150HP Bluewater Series

Look for another boat, this motor has severe problems. Sounds like it has 1 piston gone, and 2nd one almost gone. That is if the compression gauge is correct.....

 

[tarheelborn66]

Re: Compression Problems with 1999 Mercury 150HP Bluewater Series

Thanks for your comments. How much would it be to replace the power heads on this engine?