1979 80 hp mercury outboard ignition timing problem

[gwt3383]

I acquired a boat and motor (see discription of motor above) as payment of a debt. I went through everything (cleaned gas tank and new fuel, cleaned carbs, new plugs, etc. I ran but wouldn't idle good. My son who was assisting me adjusted all the screws (3 of them) on the levers on the left side of the engine. I found another idle speed adjustment on the cable where it enters the motor housing. It runs good, idles good,etc but when I put it in the water and apply load it dies immediately. I think the ignition timing is screwed up and I need to know how to adjust it back to where it was. Anyone, please help with advice!

 

[Silvertip]

Re: 1979 80 hp mercury outboard ignition timing problem

The problem is that idle mixture was adjusted while running on muffs. Once you get it int the water, exhaust back pressure alters the idle. You need to readjust mixture and idle speed in the water. You should also buy a service specific to your engine and perform the link & sync procedure which synchronizes the carbs with each other and with the ignition timing.

 

[rodbolt]

Re: 1979 80 hp mercury outboard ignition timing problem

hello<br /> what is the engine compression? and do you have a service manual or are ya winging this one?

 

[BaysideMarine]

Re: 1979 80 hp mercury outboard ignition timing problem

These particular engines had a real sensitivity to wear. First of all, set it up according to the Merc manual.<br /><br />What tends to happen with them is that as they wear they will idle fine (in or out of the water) but when they are put into gear they will die. <br /><br />At this point, assuming you set everything up as per the manual (and if you dont do this then there is no point even talking about it) if it still dies then basically the motor is knackered, rooted, or cactus (not sure of US slang). The only way to keep it going is to raise the idle rpm to around 1000rpm out of gear. That way, when its dropped into gear it will still keep running.<br /><br />Cheers,<br /><br />Nicholas

 

[gwt3383]

Re: 1979 80 hp mercury outboard ignition timing problem

Originally posted by rodbolt:<br /> hello<br /> what is the engine compression? and do you have a service manual or are ya winging this one?

The compression is good, about 150 psi on each cylinder and I don't have a manual. I think my problem is that the ignition is not advancing when I give it more fuel for increased speed under load. All the adjustments have been tinkered with while trying to set the idle speed. Do you know the timing adjustment procedure?

 

[gwt3383]

Re: 1979 80 hp mercury outboard ignition timing problem

Originally posted by gwt3383:<br /> I acquired a boat and motor (see discription of motor above) as payment of a debt. I went through everything (cleaned gas tank and new fuel, cleaned carbs, new plugs, etc. I ran but wouldn't idle good. My son who was assisting me adjusted all the screws (3 of them) on the levers on the left side of the engine. I found another idle speed adjustment on the cable where it enters the motor housing. It runs good, idles good,etc but when I put it in the water and apply load it dies immediately. I think the ignition timing is screwed up and I need to know how to adjust it back to where it was. Anyone, please help with advice!

 

[gwt3383]

Re: 1979 80 hp mercury outboard ignition timing problem

Okay, I got it. I kept adjusting the timing until it runs and carries the load. Thanks to those who helped by replying.