Adjusting linkage cables on 81 Mercury 50 hp outboard

[TimStarforth]

Hi. I just replaced the impeller on the water pump, and now I need to know how to adjust linkage cables on 81 Mercury 50 hp outboard, both throttle and shift cables. I purchased from an individual, and I think they might have hit something. Looks like a brand new prop, but on land with earmuffs, prop spins in forward, and rpms go up...however, on the water, the boat wants to die on me, and moves forward, but not very fast. Could the prop hub be the problem? No cracks or dried water, but could the hub be bad if they hit something? Thanks, very frustrated and stumped.
Tstarforth

 

[Lone Duck]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Hi. I just replaced the impeller on the water pump, and now I need to know how to adjust linkage cables on 81 Mercury 50 hp outboard, both throttle and shift cables. I purchased from an individual, and I think they might have hit something. Looks like a brand new prop, but on land with earmuffs, prop spins in forward, and rpms go up...however, on the water, the boat wants to die on me, and moves forward, but not very fast. Could the prop hub be the problem? No cracks or dried water, but could the hub be bad if they hit something? Thanks, very frustrated and stumped.
Tstarforth

It sounds to me like the back pressure in the exhaust is causing a poor running condition when boat is in the water. You should do a compression check , electrical check, and your whole fuel system including carbs.

 

[TimStarforth]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

You don't think the prop hub could be the problem? I have since adjusted the linkage on the cables, and checked all fuel lines, filters, and vents. Electrical is good, fuel system is good....it runs fine in the yard, so I don't think it's compression either. I think the prop hub is causing the prop not to spin. It moves forward in the water, but barely. Will the prop still turn if there is lower end damage
Thanks for your reply!
Tstarforth

 

[Lone Duck]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Hi. I just replaced the impeller on the water pump, and now I need to know how to adjust linkage cables on 81 Mercury 50 hp outboard, both throttle and shift cables. I purchased from an individual, and I think they might have hit something. Looks like a brand new prop, but on land with earmuffs, prop spins in forward, and rpms go up...however, on the water, the boat wants to die on me, and moves forward, but not very fast. Could the prop hub be the problem? No cracks or dried water, but could the hub be bad if they hit something? Thanks, very frustrated and stumped.
Tstarforth

You said( the boat wants to die on me) Do you mean the engine stalls or slows down? Or do you mean the engine revs but boat will not pick up speed.

 

[Maxz695]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Mark the prop nut or thrustwasher then mark the prop take it for a try and come back and see if the lines are still in the same position. This will tell you if the prop is spining and not grabbing. JMO bogging can be as simple as a slight carb adjustment. Bring the mixture screw out on the carb or carbs a bit at a time until the engine surges nicely when throttling up to get a FAST response and great holeshot.

 

[TimStarforth]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Revs but doesn't pick up speed, and dies sometimes....Thanks!

 

[Lone Duck]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Revs but doesn't pick up speed, and dies sometimes....Thanks!

Yes it is probably your hub. Sorry I misunderstood you. Take note of Maxz695's post.

 

[TimStarforth]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Thanks so much! Checked all the things you listed, and sure enough there were two fuel lines with small rips in them. Took it out on the water today, and she ran just fine!

 

[Lone Duck]

Re: Adjusting linkage cables on 81 Mercury 50 hp outboard

Great!! Happy boating.