78 mercury outboard throttle problem

[thunderbolt1977]

Ok here it goes the motor was running great this year until it took on some water and stalled out. I dried out the motor with a blow dryer and by good old sunlight. It was having a hard time starting but now fires right up on the turn of the key. After that problem fixed itself the motor was having trouble idleing. So i drove it around the lake at a slow speed and let it work its way out. Now it is idling like a champ. Now my next problem is when i give it gas to take off there is no take off. It only has one gear it seems like and thats a little bit faster than idle. The motor wants to take off you can hear it trying to and it will start to and then just die down to a slow idle. I have cleaned the carbs, checked the switch box, and checked my fuel pump, and spark to the cyclinder all good. Dont know where to go from here any ideas please help i have a bass tourny coming up in two weeks and would like to have her up and running.



PS is it normal for the motor to be sparking like a xmas tree when it is running from the coil and distributor that seems a little odd to me, but like i said runs better for starting than it has ever.

 

[CharlieB]

Re: 78 mercury outboard throttle problem

sparking like a xmas tree

NOPE!

sounds like that water wasn't quite all gone before you first started it. Arcing from a coil or distributor cap will burn a carbon trail, leaving a lower resistance 'path' which will arc again when engine load increases.

Disassemble the plug wires, dry inside all the boots, make sure they all fit tight, maybe a small spot of WD inside each.

Closely inspect the dist cap inside and out for any hairline carbon trails. Same with coil. You may get lucky and erase all signs of a carbon trail with 220 emery cloth, not to aggressive, just use it like you are erasing a pencil line, otherwise replace the cap.

 

[thunderbolt1977]

Re: 78 mercury outboard throttle problem

alright that fixed the spark issue but still wont go when i give the motor gas does anyone have any idea of where i should be looking now it is like a never ending circle with this i fix one thing in another goes bad. It was running great until water got inside the cover on a rough day and stalled out.

 

[CharlieB]

Re: 78 mercury outboard throttle problem

No more arcing?

Now check to be sure that the ignition is capable of throwing at least a 7/16 inch arc at the spark plug end of each wire. Any less and the motor cannot fire under WOT.

 

[Chris1956]

Re: 78 mercury outboard throttle problem

Thunderbolt, You likely have the carbs idle mixture set too lean. Richen them up 1/8" turn, one at a time starting from the top carb, and testing between each adjustment.