1978 merc 80 horse issue

[fireguyfire]

Hi Guys;
I have a 1978 merc 80 horse outboard that has run like a top until 2 weeks ago, when my boat got partially swamped; the motor got wet upto the point of the bottom of the cowling cover. Even though it barely got wet, I did the complete submersion overhaul suggestions in the shop manual, and luckily there was no water in any of the cylinders. My problem is this; the motor starts fine with the start lever fully up( before it only needed to be half up to start), and will idle all day at full throttle, but if you put the lever down to half (which is where it should be to start n an 80) it barely stays idling, and if you go to bed the lever, it dies. I tried taking the lever down to half, and then put the propeller in forward, revved it up a bit, and then I could bed the throttle lever, and (with muffs on) I could easily take the motor to any speed I wanted, and it runs great; BUT, as soon as you put the throttle back to neutral, it dies.
Any ideas why after being partially swamped it will not idle? Nothing on the engine was touched, or changed, and i dont want to start monkeying with settings because as I said it ran like a dream before. Any ideas?

 

[Chris1956]

Re: 1978 merc 80 horse issue

That is a symptom of clogged low speed passages on the carbs. Did you get water in the lower carb? Water in the fuel? Drain the lower carb into a rag. Water will beed up on the rag.

 

[fireguyfire]

Re: 1978 merc 80 horse issue

I changed the fuel in the tank, and the filter; what is the easiest way to drain the lower carb out?

 

[Chris1956]

Re: 1978 merc 80 horse issue

There should be a brass plug over the main jet in the bottom of the carb. Remove it and the fuel will drain.

 

[fireguyfire]

Re: 1978 merc 80 horse issue

Thanks Chris! Will give it a shot and see if that helps.