1981 80hp Mercury

[Mallardz59]

I have an '81 Merc which has not been used for approx 3yrs. I replaced all the fuel(Ethanol-free) and it starts up ok with the fast idle forward. However it will not come to an even idle so that I can shift it into gear. It seems to sputter just a little at WOT on the throttle but I dont think it is getting WOT. Prob cost me a hunting trip this am. Any suggestions?

 

[ibnfshn]

Carbs are probably gummed up from sitting so long. You might luck out by running some Sea Foam thru it. If not the carbs will need to be rebuilt. Also make sure you are not sucking any air in thru fuel lines. They must all be soft and pliable, especially the primer bulb as it is usually the first to go.

 

[Mallardz59]

Thanks. Ill refit my fuel line tomorrow & look for some Sea Foam. Hopeful that works.

 

[fastjeff]

Also try opening the idle mixture adjustments CCW about 12 turn.

Jeff

 

[racerone]

Open idle mixture about ----1/2 a turn ---------and try that.

 

[Mallardz59]

Which screw is that? Im not quite qualified as a Merc mech yet...LOL

 

[guyjg]

You might luck out by running some Sea Foam thru it.

In order for it to dissolve fuel gum/varnish it has to be introduced into the carb...fuel strength works overnight. Drain the carbs and remove the fuel line at the carb. Use a can of Seafoam spray w/a nozzle and fill the carb. Reinstall the fuel lines and wait a day or two. When you start it up it will smoke like it's on fire...the smoking will stop when the Seafoam burns off.

 

[fastjeff]

Yikes! What a dumb typo! I mean to say "1/2 turn" not 12!

The idle mixture screws are located in the top left side of the carbs and are a screw driver slot type screw.

Jeff