1969 Mercury 20hp help

megaboat2003

Recruit
Joined
Jan 26, 2008
Messages
2
A friend gave me a 1969 20hp Mercury for my Jon boat. It looks to be in very good condition, but hasn't run in years. It turns over nicely and has good compression, was stored inside so it looks good, Question... is it worth fooling with being it's age and the availability of parts for it, I've got to admit...a 40 year old motor may require more fiddlin' with than I'm ready to do. But, you Mercury guys out there may say it's worth the time, maybe these were great motors...I don't know. Any comments appreciated..negative or positive. Thanks !
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 1969 Mercury 20hp help

Howdy Megaboat.

Welcome to iboats. :)

Well, I am not a Merc fan but it is surely worth "fixin up".

It needs these things for sure:
*Replace impeller.
*Clean carb. That means clearing all tiny passages and orifices, not just make it pretty.
*Drain and refill foot. Be sure to use new gaskets on drain and vent plugs.

Good idea to also:
*Clean and gap plugs.
*Clean and gap points.

Then fire her up. Forty is not old for a well maintained outboard. Parts are available.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: 1969 Mercury 20hp help

WOW! That's my kind of friend! Those old merc 20's will run like a 25hp motor.... Huge amount of low end torque. It will really go fast on a 14 ft. aluminum boat with the 2 bladed prop. Do all of the aforementioned things and you'll love it as long as the electrical parts are good and your carb is perfectly cleaned and tuned. You also need to keep a close eye on the lower unit oil because it'll probably leak. I'd just change it regularly if it doesn't leak too bad, rather than trying to get it perfect, which you may never do. Definitely worth fixing! I'd love to have another one.... Those are sharp-looking motors, too.
Good luck,
JBJ
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1969 Mercury 20hp help

As was pointed out, keep an eye on the lower unit oil. Pre mid-1970s Mercs use carbon steel shafts that are prone to rusting near the seal areas, particularly under the waterpump cup where water can puddle and create its havoc.
I have a 20hp that I run fairly regularly on my 14-foot Starcraft tinnie. Goes like stink!! Red stripers are my favorite of the black-era Mercs...
- Scott
 

megaboat2003

Recruit
Joined
Jan 26, 2008
Messages
2
Re: 1969 Mercury 20hp help

Thanks for the replies. Pulled flywheel and cleaned points and established spark, will fire up on fuel squirted in cylinders. Looked for carb kit...hard to find if at all. Question....are there people or businesses that sell reman carbs, or services that I could send the carb to and have it professionally rebuilt. Again, any help appreciated !
 

Kajun37

Petty Officer 1st Class
Joined
Feb 17, 2006
Messages
348
Re: 1969 Mercury 20hp help

you should be able get a carb kit from your local mercury dealer...just call and give them the model and serial # on your motor......dont squirt just straight fuel in your carbs be sure its mixed with oil 50:1...get the kit and rebuild it yourself its very easy once you get into it.
 

WOODCHUCKER

Cadet
Joined
Oct 29, 2010
Messages
19
Re: 1969 Mercury 20hp help

I have a 1969 merc 200 20hp phelon flywheel magneto ignition with no fire on either cylinder.Has good compression,installed new points,condensers,still no fire.The push part of the stop switch is missing.Does this affect firing? flywheel has strong magnets,is it possible for both coils to be bad? Any help appreciated.
 
Top