1982 merc 80 hp stalls when I put it in gear

profgolf1

Cadet
Joined
Jun 29, 2010
Messages
18
I cleaned and rebuilt the carbs this spring, checked the timing today and replaced the plugs.
I can get it to idle fine.
But when going into gear it drops rpm till it stalls, when in the boat is in the water.
I have followed the "Timing and Sync of Merc Inlines (to 1988)"
I have turned out the mixture screw out on each carb.
If I bump up the throttle it will stay running, rpm's have to be over 1000.
Any ideas on what to check next?
 

profgolf1

Cadet
Joined
Jun 29, 2010
Messages
18
update
this morning I did a compression test, cylinders 1,2 and 3 all around 120 psi, very little variation maybe 5 psi.
I don't have an adapter to get at cylinder 4.
When I pulled the plugs 1 and 2 were black, rich mixture? 3 and 4 the porcelan is white, lean mixture?
I am going to pull the carbs again to see if anything is plugged.
I should add that I rebuilt the fuel pump in spring as well, there was an update for that.
 

Masonmoore

Seaman Apprentice
Joined
Jul 30, 2015
Messages
37
I have the same problem with my mariner, and it also idles fine. Exept mine stalls imediatly when you put it in gear unless the fast idle is engaged
 

Glavini

Cadet
Joined
Jun 19, 2012
Messages
23
My motor is also stalls when put into gear. Will idle fine, also works well on muffs but when it's in the water I guess there's just to much resistance and it dies. I've read a good amount and talked to some people who told me to clean the carbs.....looks like I'll do that tomorrow. How many carbs, from what I read it seems like 2. I bought a gasket kit from west marine but I only purchased 1. Will I have to buy another?

In your case, could it be the carbs are gummed up again? When was the last time you took it out? It seems like it only takes a couple weeks of non use before the oil starts to gel up. Maybe you need another cleaning?
 

profgolf1

Cadet
Joined
Jun 29, 2010
Messages
18
Does anyone know the idle and max advance on this engine?
1982 80hp 4 cylinder.
I set the timing with the engine running today, at idle 3 deg. before tdc
It still stalls when going into gear BUT now if I give it enough throttle to keep it from stalling I can throttle back to idle and it stays running.
The idle timing was at 5 deg. before tdc when I started.
How much can I advance the idle timing?
 

Glavini

Cadet
Joined
Jun 19, 2012
Messages
23
So I'm not sure on the timing but since I had put new cables on the motor I had to adjust the idle. Took her out today and everything worked just fine.
 
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