1985 50 hp mariner no speed

[Johnnyboy454]

Re: 1994 50 hp Mariner no speed???

Re: 1994 50 hp Mariner no speed???

Any help would be GREATLY appriciated!!!

I have a 1994 50hp Mariner and its bogging down on me from just the other day. It starts up fine and idles good until I give it alittle past 1/4 throttle planes for about a second and then starts screaming like the engines outta the water? If I give it past 1/4 throttle the rpms just get louder especially with the noise but it goes no where? I checked the prop but it checks out ok? Could someone please help me with this! Im 16 and this is my first real outboard that I saved up to get. Any help would be most appriciated, thanks Johnny.

 

[pompeymatt]

Re: 1985 50 hp mariner no speed

russell, i have the exactly same engine as you and mine is doing the same....

outboard engineer said the spark plugs were faulty, however i changed them and problem is still happening..

he said to check coils, if not check switch box...

however your commpression is fairly low, mines 160 on all cyls..

you may be loosing power due to the commpression?just a thought..

hope you get it sorted

 

[jeffersondodson561]

Re: 1985 50 hp mariner no speed

If you say that the motor sounds good but you have no speed have you checked if your prop is spun? Have another prop?

 

[makinhole]

Re: 1985 50 hp mariner no speed

Had the same problem with a 68 merc 650. ran like it would do back flips in a barrel, put it on the lake and it would barely make a wake, finally I gave up and bought a newer outboard. I spent about 100 hrs on it and could not figure it out, I hope your persistence pays you better dividends than mine. Good luck!!!

 

[derrick0823]

Re: 1985 50 hp mariner no speed

I have a 1985 50 hp mariner 4cyl and was having the same problem. I replaced much of the same things you did trying to figure it out. It turned out to be the fuel pump/diaphram on mine which is included in a carburator rebuild kit but, not included in a gasket kit. On mine I noticed (after having the WOT building to only 2k RPM's issue)when the engine sat after running I would have an oily residue leaking from the lower unit around the exhaust port. At the time I thought well great there's another problem to deal with but, it turned out to be the very clue to the mechanic as to what the problem was. After all the time and money I sank into this thing trying to get it running it took my local Mercury/Mariner mechanic about 2 minutes to diagnose it, a couple hours to clean and rebuild the carbs with new fuel pump and it only cost me $100. I am back on the water and it is running perfect!

I didn't read all of the posts on here so I hope I am not repeating some one else.