1986 merc 850

abcauto6845

Recruit
Joined
May 24, 2009
Messages
1
hello all and thank you in advance for any help! i am looking at buying a boat with a 850 merc outboard i think it is a 1986 the owner says it has engine issues when he puts it in gear it wants to stall and when he does get it to go it only does like 15 mph i did a compression check on it it has between 78-82 in all 4 cylinders but im unsure of what the spec is any help would be great. thanks to all!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,846
Re: 1986 merc 850

That compression is way out of specs. It should be 100PSI +. Either your gauge is bad, or the motor has been run w/o oil. It will need a complete rebuild, which will cost $700 in parts plus labor, if you send it out.
 
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