What would be bottom line compression on a '97 Mercury 250EFI if you were looking to buy?
What would be bottom line compression on a '97 Mercury 250EFI if you were looking to buy?
"Give a man a fish and feed him for a day...teach a man to fish and, he'll lay out of work, miss dinner dates with the wife....and live happily ever after"
"He, who dies with the most toys, wins"
The manual lists a specification of 90-110 PSI, with a maximum difference of 15 psi.
Compression tests should be taken on a WARM ENGINE, with a FULLY CHARGED BATTERY, and the throttle plates WIDE OPEN.
If you have any serious question of the health of the engine, you might consider a LEAKDOWN TEST (which is a MUCH more accurate measure of the "health" of the engine).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Thanks... Compression test was 94 to 96 on all six. This is an offshore 25" 250 EFI. Don't know if the manual is different for the offshore. And also, this is a 1999 not a 1997. Type-o...sorry.
"Give a man a fish and feed him for a day...teach a man to fish and, he'll lay out of work, miss dinner dates with the wife....and live happily ever after"
"He, who dies with the most toys, wins"
Your compression numbers are well within spec.
However- I don't think you'll be happy with a 25" model on your boat....
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
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