94' mercury problem

Kwaynem

Seaman Apprentice
Joined
Mar 8, 2016
Messages
34
I have a 94 40 HP Mercury and it acts like it has no power when you give it full throttle to take off it don't even raise the bow of the boat up. I pulled the top off and checked it in neutral then put it in full throttle position the bottom is all the way over against the stop and the top linkage doesn't even look like it moved
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
The bottom, carburettor? Top linkage, spark advance or carburettor, or something else?
Also, around that era, Merc had a 2 cylinder, a 3 cylinder and a 4 cylinder 40hp... Could we have an engine serial number please?

Chris......
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
4 cylinder, electric start, long shaft with oil injection... (ELO, not the band :D)
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
ELO means Electric start, Long shaft, Oil injection.

ELO means Electric Light Orchestra.


Good one. Chris. LOL
 

Kwaynem

Seaman Apprentice
Joined
Mar 8, 2016
Messages
34
Lol remember electric light orchestra I guess I'm out of my league on the other lol
 

Kwaynem

Seaman Apprentice
Joined
Mar 8, 2016
Messages
34
So no suggestions other than dig out my old cassette tape collection?
 

titaniumneck

Petty Officer 1st Class
Joined
Apr 11, 2016
Messages
209
Put in a barrel, and timeing light on it make sure timing is advancing. Maybe first check compression on all cylinders. A motor can sound great and not miss, but have no power because one cylinder has no compression. Mine did that, bad compression on top cylinder, luckily it was just blown head gasket.
 

25xs

Cadet
Joined
Sep 30, 2008
Messages
22
I pulled the top off and checked it in neutral then put it in full throttle position the bottom is all the way over against the stop and the top linkage doesn't even look like it moved

I think you have answered your own question... If the carburetors are not BOTH opening / actuating with the throttle, then you have likely broken the black, plastic linkage part between the two carburetors. It is Part No. 53719A2 and found here on iBoats:

http://www.iboats.com/Boat-Parts-Ac...--searched.1--filter.prod_name?q=53719a&s=sol

If you look it up in an exploded parts view, it is NOT found on the page with the carburetor, rather it's in the view of the fuel pump, picture key #30 between the "ghost images" of the two carburetors.

Tom
 

Kwaynem

Seaman Apprentice
Joined
Mar 8, 2016
Messages
34
Thanks Tom if I checkthe compression a guy told me to pull all spark plugs then turn the motor over with the key and check the guage I did this and each cylinder read 8psi sounds like it's the wrong way to do it
 
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