What year Mercury?

merkdawg0084

Chief Petty Officer
Joined
Oct 11, 2017
Messages
573
Looking at 9.8 mercury or 9.9 depending on years. Are there any particular years that were just really bad motors? I know the Evinrude 9.9 and 15hp 74-76 were not the best years. Thx
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Not really. The 9.9 will be newer than the 9.8 though and above all else and with any purchase of an older 2 stroke....a compression test is totally essential
 

looserivet

Cadet
Joined
Feb 18, 2018
Messages
23
I've got both a 1973 Mercury 9.8hp and a 1974 Evinrude 9.9hp, while both are good motors, the Mercury is the more finicky when it comes to the carburetor. I've rebuilt that thing 20 or more times. The Evinrude just goes and goes. both have had new fuel pump diaphragms an a half dozen water pump impellers over the years. The Evinrude is the stronger motor but its also a heavier motor and likely a bit larger displacement.

I never heard that the '74-76 Evinrude 9.9-15 hp motors had any issues.
As with any long running model, improvements were made over the years but none were 'bad' motors.
The only Evinrude products I stay away from are those with electric shift, and Ficht motors, but those are all much larger motors.
The first two years of the 9.9 Evinrude has points, which I don't see as a problem, but that changed by 1976.
My 1973 Mercury 110 9.8hp was my first new outboard, so it'll likely be with me till the end, the Evinrude belonged to a fishing buddy back in the day, I run the Mercury in freshwater, the Evinrude in saltwater. The stainless hardware on the Evinrude makes it the obvious better choice over the Mercury for salt or brackish water use.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
for the 7.5/9.8 11 cubic inch motor, look for after 1978 to get stainless shafts. not much change from 1978-1985 other than decals on the cowl. this will be a bit lighter than the larger 9.9/15hp version

the merc 9.9/15 was 1986 and later
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,032
There is nothing wrong with electric shift outboard motors !!-------There is something wrong if you needed to REBUILD a carburetor 20 times !!----Clean the carburetor once every 20 years maybe.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
I've got both a 1973 Mercury 9.8hp and a 1974 Evinrude 9.9hp, while both are good motors, the Mercury is the more finicky when it comes to the carburetor. I've rebuilt that thing 20 or more times. The Evinrude just goes and goes. both have had new fuel pump diaphragms an a half dozen water pump impellers over the years. The Evinrude is the stronger motor but its also a heavier motor and likely a bit larger displacement.

I never heard that the '74-76 Evinrude 9.9-15 hp motors had any issues.
As with any long running model, improvements were made over the years but none were 'bad' motors.
The only Evinrude products I stay away from are those with electric shift, and Ficht motors, but those are all much larger motors.
The first two years of the 9.9 Evinrude has points, which I don't see as a problem, but that changed by 1976.
My 1973 Mercury 110 9.8hp was my first new outboard, so it'll likely be with me till the end, the Evinrude belonged to a fishing buddy back in the day, I run the Mercury in freshwater, the Evinrude in saltwater. The stainless hardware on the Evinrude makes it the obvious better choice over the Mercury for salt or brackish water use.

They used points on the first 3 yrs of the Evinrude 9.9/15 hp 74-76. It is common knowledge these are troublesome motors.
 
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