merc 850 K

percula 9

Cadet
Joined
Jul 1, 2008
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6
I have a 1956 mercury 850, runs good,but shows no water venting out. Does this model vent water underwater? I've seen no hole for the water to come out. Motor doesn't get hot, I can remove outer shields and hold my hand against engine.
 

Laddies

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Sep 10, 2004
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12,218
Re: merc 850 K

Therr were no 850s in 1956 but there have been many differant model 850 engines built, a serial number would help.
 

percula 9

Cadet
Joined
Jul 1, 2008
Messages
6
Re: merc 850 K

Sorry, typo it's a 1965 mercury six 850 85hp kiekhofer, serial#1650244,dual distributor, points, what-not, found out today she has low compression, water in lower unit timimg and idle is off. repairs will cost more than she is worth. hard to find parts for,tuning her is a real chore any suggestions?
 

Fuzzytbay

Chief Petty Officer
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Jun 6, 2008
Messages
557
Re: merc 850 K

Ok guess I'll ask.
In your first post, you said it runs good. I assume your having doubts about the waterpump. My guess is you bought it to a shop. They tell you all is "not good"::(.It will cost you "this much", but we'll sell you a new one.
First off compression is more about being equal, than meeting the "orginal"
values. If your cylinders read within 10Lbs of each other, and are not much less than say 80% of new values, then it should be fine. As for the timing being off, the link and sync is relatively easy for these motors, if your a bit mechanically inclinded, and can follow it step by step. Water in the lower unit is also an easy fix, unless you ran it full throttle over some rocks since you have owned it. :rolleyes: somehow i don't think you did.:cool:
 

percula 9

Cadet
Joined
Jul 1, 2008
Messages
6
Re: merc 850 K

Thanks that makes a lot more sense, a 43 year old motor is going to have a loss of compression.
 

Fuzzytbay

Chief Petty Officer
Joined
Jun 6, 2008
Messages
557
Re: merc 850 K

You might want to consider doing a "seafoam" and "Deep creep" treatment to the motor. Sometimes, on older motors the rings get stuck up (Newer motors too). These two products really work, and will deffinatly make an improvement in motor perfomance. If you do a search on the forum, using the word "Seafoam", you will find out the how and why's of it.
 
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