18 HP OB Block replace

LindenLongRods

Petty Officer 2nd Class
Joined
Jul 10, 2007
Messages
192
I have a 18HP Evinrude OB, with pretty bad corrosion on the block, from salt blockage (Not Me). Thinking about replacing it. I definitely can't do. How much Ballpark figure? any recommendations?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
If it is something you need to pay somebody to do, it isn't worth it. Get another motor.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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50,429
spend $200 on a complete motor.
 

jimmbo

Supreme Mariner
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May 24, 2004
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13,696
Unless that motor has some great Sentimental valve, it would be cheaper to get another, preferably unsalted motor
 

RCO

Petty Officer 1st Class
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Jun 15, 2016
Messages
350
It is about an hour job with basic hand tools if you have never done one before. Should be able to find a good used powerhead for less than the cost of one hour in labor at a Marina .
 

thatone123

Banned
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Mar 7, 2009
Messages
707
In many areas of the country you can find the old 20/25/30/35's etc for cheap and many still run and/or have good compression. Those 22 CDI engines are among the best even made by OMC..tough as nails, no CDI's to go out and bullet proof with lots of raw power not available in a 4 stroke.
 

thatone123

Banned
Joined
Mar 7, 2009
Messages
707
!8-20-25 were the venerable 22 cid block. I use 20 a lot and found 2 alike for $100 each. Both ran fine. 1 needed gear case seal replacement and the other will get the job this winter. Also water pumps of course. Easy gearcase to work on! Kid could do it. Put window strips black rubber strips 1 1/2 or wider if you can fine em' on inside of cowling. Tape these to the inside of the cowling and wa la almost as quiet as a 4 stroke. If you need to start outboard below freezing, on these an others small older OMC I take out all natural safety switch gizmos so you have higher throttle for starting. Just make sure you don't start it in gear. These are very light outboard powerful outboards like nothing available today
!
 

LindenLongRods

Petty Officer 2nd Class
Joined
Jul 10, 2007
Messages
192
Thanks for the replies, I have the serial number written down somewhere. It is from the 70's, great engine. Still runs, but for the block. So I understand though. I would change the whole powerhead and not just the block, correct?
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Yep, and flush with fresh water the new powerhead soon after boating specially on salt waters, will last longer with much less salt build ups on entire water paths.

Happy Boating
 

54bobby

Petty Officer 2nd Class
Joined
Dec 12, 2010
Messages
181
my dad bought a 25 evinrude new in 1969, the first year for the 22 cubed 25 hp. other than water pumps she has needed practically nothing. this year has been the first she has given any problems in the 49 years i'v had her and that was points, bib deal. and as a while i'm in there type thing i will redo the entire ignition system. oh yea, a clutch dog too. still have the factory box it came in. great series of engines. i went out and bought 2 more 25's for parts along with 3 18 fastwins. i now have 6 of those 22 cubic inchers for parts but can't bring myself to start cannibalizing them cause they all run so good.
 
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