'81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on water.

TimStarforth

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I am trying to find a part for my 81 Mercury 50 hp motor that is missing. Motor is running fine now in forward, however, when I put the motor in reverse, the reverse lock hooks are not locking, and motor is lifting up. I am trying to find a schematic for the motor, because the seloc manual doesn't tell the name of the part I am missing, so I cannot locate the part. Does anyone know where I can find the schematic for this, or even the name of the part that goes from the reverse cam up to reverse lock hooks. Also the positioning of the reverse cam on the lower end would be helpful.
 

carholme

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

What is your engine s/n?

Gerry
 

carholme

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

What is your engine s/n?

Gerry
 

TimStarforth

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

5950371. I have had people tell me that this motor is really an '82, in spite of the title, because of the serial number range.
 

carholme

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

That s/n comes up as:


MERCURY - ( 50 H.P. (1980 ))
Serial No: 05950371 Model No: 1050520

Parts List for model 1050520:

45/50 H.P. - Mercury, Mercruiser, Force, etc. Parts Lookup

Service Manual for your engine is P/N: 90-86135--5

Some excellent prices here:

MERCURY MARINER OUTBOARD SERVICE MANUAL 45 50 60 70 P N 90 86135 5 | eBay

In the interim, here is a link to the condensed version of the Clymer manual which will help you with your questions. Download it soonest to your computer as the link is short lived:

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR-CYLINDER MODELS (1969-1989).

If you look in the parts list under SWIVEL BRACKET AND REVERSE LOCK you will see everything above the reverse lock cam.

On page 287 of the Clymer manual, you will see fig M12-64 and this is the positioning for the reverse cam when mounted on the lower shift rod.

Gerry
 

carholme

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

PS., forgot to ask you if you have Tilt/Trim on your setup?

Gerry
 

TimStarforth

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

No tilt/trim on setup, thanks!
 

TimStarforth

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

Thank you! What I need is the push rod, spring, nut and washer. On the parts list, it says it is no longer available, and No compatible aftermarket products are available. Any ideas on where I might find one? I have checked most of the boat salvage yards here in Missouri. Thanks again for all your help!
TStarforth

Can you also tell me how you determine if my engine is a short or long shaft. There are several choices for the push rod....one is part 25 on schematic, one is 25-1, one is 25-2, etc., depending on engine is short or long shaft. Then there is part 28 in a box to the right. Not sure which setup I have....seems like the only difference is a nut versus a washer pivot screw.
 

oldman570

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

If you measure from the top of the transom to the cavition plate should tell you if the motor is a short shaft 15 to 17" or a long shaft 19 to 20" motor. You can check with the stickys on here and get a list of other salavage dealers that might have the parts you need. I have an old 50 out back and will check it and see if the parts you need are the same. I doubt they are as I belive the motor is older than a 1980 and closer to a 1970.JMO
Oldman570
 
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carholme

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

Beside item 25 is very important information which will start to narrow down your search.

Notes: UNITED STATES 5796396 AND UP AUSTRALIA 8069215 AND UP BELGIUM 9291996 AND UP CANADA 7165753 AND UP

You s/n is 5950371, therefore it matches US 5796396 and up.

Whether or not your engine is still in the original configuration as delivered from the factory, here is a link to show you how to measure the engine itself:

Outboard Motor Shaft Length

Gerry
 

CharlieB

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

Thank you! What I need is the push rod, spring, nut and washer.............

Are these parts missing or damaged?

Have you checked the reverse lock cam on top of the gearcase?

The cam has a habit of wearing a grove into it from the rod, digging a trench in the ramp so deep that it will no longer lift the rod far enough to engage the lock.

Or someone may have indexed the cam incorrectly and the rod is not on the ramp.
 

TimStarforth

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

Part is missing, cam is the first thing I checked. It is indexed correctly. Thank you!
 

TimStarforth

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Re: '81 Mercury 50 hp reverse lock hook is not locking when boat is in reverse on wa

OK. I have the yoke and the hook locks. I just need the rod, spring, washer, and nut. So part number 28 only says later models, no SN listed on that part, so it is still a bit confusing. Part 25, which fits my SN, is the whole assembly, and 148 dollars, but there are none to be found. Hopefully someone on here will know where to get the part!

By the way, it is a long shaft, Gerry! Thank you.


OK. So I think we found it! We found part #47836, and just ordered the nut for that one. Seems to be the only difference. We were told either push rod would fit, you just have to have the correct nut for the correct push rod. This particular one has no spring or washer with it, so all we needed was the nut. Thanks for all your help!
 

carholme

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