1979 Mercury 80hp bogs down and dies

[crzytrn]

I have a 1979 80hp that will putt around great, but when you run WOT it bogs down and stalls out. Hard to restart. When it does restart as soon as you put it in gear it dies. I've replaced, fuel line from tank to quick connect and from fuel pump to carbs. cCarbs supposedly have been recently rebuilt. I can smell gas after motor dies.

 

[tbonebrad]

Re: 1979 Mercury 80hp bogs down and dies

I have this exact same problem with this motor and I would love to know what the heck is going on too.

 

[downintime]

Re: 1979 Mercury 80hp bogs down and dies

The carbs or fuel pump should be cleaned or replaced. It sound like a fuel starvation problem at higher rpm and wot. Just cause you smell gas does not mean it is getting enough. It is hard to restart because the pump and or carbs need to refill with fuel. Do you have to pump the bulb to get it to restart?

 

[CharlieB]

Re: 1979 Mercury 80hp bogs down and dies

It could be either the idle mixture is still a bit too lean, the fuel pump is weak and cannot supply enough to keep the carb filled, or air leaking into the fuel system.

Start by disconnecting the fuel hose to the carbs, point it into a suitable container and crank the motor, watching the fuel stream, it should be a solid pulsed stream, fat as the hose and at least and inch or more from the end of the hose.

A second test, install a clear hose between the fuel pump and carbs, run the motor and watch for air bubbles passing thru, indicating air sucking in somewhere.

REMEMBER to remove that clear hose once finished testing and repairs, clear hose is NOT rated nor approved for fuel use, ONLY as a short term testing tool.

If both these check out fine then try opening the idle mixture screws, turn each just the width of the screwdriver blade slot and retest acceleration, if it improves but not fully cured, repeat until perfection.

 

[Skyler19]

Hey I am having the same problem runs great when not under load after idling for a bit it bogs down and stalls some times so I first tried, new tank hose and inline filter cleaned the carbs and ran it with "ear muffs" and it ran fantastic now I took it out on the river ran good for maybe 15 mins and them had a hard time starting it wouldnt fire unless I had the idle on full to start and if it didnt start first try I would have to choke it with the idle on full then it will cruise and putt around at low rpms but the moment you start to gun it, it dies but if you really baby it super slow it will pick up and sometimes goeS WOT No I havent changed plugs yet next on the list jist didnt find them at canadian tire

 

[Skyler19]

Hey I am having the same problem runs great when not under load after idling for a bit it bogs down and stalls some times so I first tried, new tank hose and inline filter cleaned the carbs and ran it with "ear muffs" and it ran fantastic now I took it out on the river ran good for maybe 15 mins and them had a hard time starting it wouldnt fire unless I had the idle on full to start and if it didnt start first try I would have to choke it with the idle on full then it will cruise and putt around at low rpms but the moment you start to gun it, it dies but if you really baby it super slow it will pick up and sometimes goeS WOT No I havent changed plugs yet next on the list jist didnt find them at canadian tire

 

[mr 88]

Skyler start your own thread,don't jack the OPs

 

[mr 88]

To the OP has the engine been Linked and Sync recently ? The transistion circuit on those carbs are terrible. Thats why it was suggested that you try opening up your idle jets . Start by going out 1/8th of a turn with each carb,then test.