How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Whitecap36 Your Own Question
Whitecap36, Marine Technician
Category: Boat
Satisfied Customers: 1545
Experience:  28 years Certified Marine Technician and past FL State Certified teaching degree
Type Your Boat Question Here...
Whitecap36 is online now
A new question is answered every 9 seconds

What should compression be on a merc 2000 225 efi engine

Resolved Question:

What should compression be on a merc 2000 225 efi engine
Submitted: 6 years ago.
Category: Boat
Expert:  Whitecap36 replied 6 years ago.
As compression is not a recommended test for an outboard engine there are no such spec's in the Mercury service manual. We have seen case after case where good compression reading are dismissed with poor leak down test readings. The only accurate compression reading is a bad or low reading. So before you make this boat purchase I recommend taking to a dealer that will check over including performing a leak down test.

To understand the leak down test better we first run the engine to operation temp and remove all spark plugs. We then pressurize one cylinder at a time with the piston at TDC and read the percentage of leakage as we move the piston down to the ports and back. This is a very accurate test and is recognized by all marine engine manufactures.

Edited by Mike on 12/4/2009 at 5:33 PM EST
Whitecap36 and other Boat Specialists are ready to help you

Related Boat Questions