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Mercury 225 EFI Compression?

This topic has 4 replies, 4 voices, and was last updated 17 years, 3 months ago by EK.

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February 28, 2009 at 2:08 am #327678

weasle111
Participant

I am looking at an 01 Cougar with a 225 efi Merc. The compression has been checked and is 120+ on all cylinders. Not sure how close all the numbers are. Is that low or about normal? The motor has not been worked on or rebuilt and is supposed to have low hours. Thanks

February 28, 2009 at 2:54 am #327697

JSLAW
Participant

I believe around 125 -135 is brand new- basically what you are looking for is that all the cylinders are pretty much within 10% of each other. If you have 120+ on all the cylinders then the compression reading is good.

February 28, 2009 at 3:53 am #327711

Bass Cat Boats
Keymaster

Thanks JSLAW, I didnt know what it should have been new. Its nice to have a little confidence booster when buying a used outboard. Thanks

February 28, 2009 at 2:40 pm #327727

Bass Cat Boats
Keymaster

Those sound good on compression.

February 28, 2009 at 3:20 pm #327745

EK
Participant

110-135 psi Variance between cylinders should not exceed 15 PSI.
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