Mercury 50 1987

[Warnerd0326]

I have a 1987 Mercury 50 horse that hasn't had much for routine maintanence. I changed the lower unit oil today and I just want to make sure that I filled it properly. I am guessing that I got about three quarters of a quart in there, which is about what came out when I drained it. I believe that it is full but I just want to make sure.

Another thing is the # on the prop is 43 73136 A40L 13P. If somebody could tell me what that means as far as ordering another that would be great too. I get that it is a 13 pitch but what is the dia? Are all outboards the same or are there right and left handed props?

This motor is on a 171CC Sea Nymph. The windshield on the center console is broken and I can't find one for this boat. It is also a 1987. Does anybody know where I could find one or have one custom made?

Thanks much
Dave

 

[WillyBWright]

Re: Mercury 50 1987

As long as you know the approximate diameter, that's all that's necessary. The critical number is the pitch. Different pitches have slightly different diameters, and different manufacturers have slightly different diameters. You just need to make sure you have the right family of props. That prop will fit roughly 35-70Hp Mercs. Measure the diameter by measuring from the center to the outermost portion of any blade and multiply by two. Ballpark is close enough. There are no counterrotation props for those. Knowing it's a 13p for an 87 Merc 50Hp is usually enough info.

Check with a Sea Nymph dealer, but you probably won't have much luck with an 87. Click on the Marine Store tab up on the left of this page and use Windshield in the Search box. Maybe you'll get lucky. You can find props there too.

The gearcase holds 11oz. If you filled from the bottom til it came out the top, you can't go wrong.

 

[Bob_VT]

Re: Mercury 50 1987

Where to start........

Welcome to iboats. I will give you a few sincere suggestions and some answers.......

First.... get a repair/maintenance manual for the motor
Second ........ Read it and highlight all the sections that apply to your model

The lower unit has a drain plug AND a top plug. They are normally filled from the lower plug with a pump mounted on a 1 quart container. You fill until you have oil coming out of the top hole..... then re-insert both plugs.

As far as the prop..... a great deal depends on use, max rpms, boat weight..... the wrong pitch prop will harm the motor too much pitch and you will not achieve top optimum rpms (you will lug the engine like startin a car in the wrong gear) and too little pitch will over rev the motor and possibly grenade the engine.

As far as a windshield...... order from the manufacturer or go to a glass shop that might be able to make you one from a piece of lexan or many companies carry windshields that may fit.

 

[BF]

Re: Mercury 50 1987

when filling the lower unit, make sure the engine is trimmed down so the anti-ventilation plate is parallel to the ground. Otherwise you get a big air bubble trapped inside the lower unit, and even though oil leaks out of the vent hole, the lower unit still can be underfilled. If it is underfilled you won't get proper lubrication of the upper driveshaft bearing.