reverse lock on mercury outboard

[r8rfan]

I recently bought an old bass tracker boat with a 40 horse mercury on it. A buddy of mine said that the motor is supposed to lock down when it is put in reverse. However when I do, it doesn't lock down. Could this just be an adjustment problem on the shaft or could it be that it's not hooked up in the lower unit? I figure if it's not working the motor will come up out of the water when I try and go in reverse. Any info would be greatly appreciated.<br /> Thanks a lot.

 

[rickdb1boat]

Re: reverse lock on mercury outboard

If I remember correctly, There should be a pair of curved "Teeth", for lack of a better word, that clamp onto the transom bracket when put into reverse. Look under the motor at the bracket and have someone move the shift lever from forward to reverse and see if it engages.

 

[r8rfan]

Re: reverse lock on mercury outboard

Hey Rick,<br /> Yes the curved "teeth" are there, but when I put it in reverse while it's running they do not engage. Matter of fact I have looked at a parts list on the net and it seems that everything that is supposed to be there is there. Not sure why it's not engaging though.<br /> Thanks for your reply. I see you are from St. Louis. Ever get to the Lake of the Ozarks much?

 

[jamiei]

Re: reverse lock on mercury outboard

If someone changed the impeller or took the lower unit off, chances are they didn't pay attention to this shaft. There's a rod that has to fit inside the upper curved piece for it to work. Thats what happened to my merc 69' 500 (50hp) and I realized it when I changed my impeller... It's worth a try. If its a plastic unit, it may be worn out also and need replacement.

 

[rickdb1boat]

Re: reverse lock on mercury outboard

Jamie is correct about the rod. I believe that it is possible to install it incorrectly and it will not function. Probably done when installing new pump. You will need to drop the lower unit and reposition it. And yes, I have been going to the lake for many years. Getting too busy out there for me though. Gonna try tablerock this year...

 

[r8rfan]

Re: reverse lock on mercury outboard

Well I guess I need to drop the lower unit and see what is up. The guy I bought it from had changed the impeller last fall. Evidently he didn't get that put back in the right position. Is there a gasket where the lower unit drops down from the rest of the motor? I've taken a couple of other motors apart and don't remember if there was a gasket or not. Doesn't seem like there was. I've checked the lower unit oil and it's nice and clean. No water evidence. I almost hate to go into it, but it must be done! I've also noticed that the plugs have unburnt gas on them. Does this mean that she is not firing hot enough? Also does anyone know where I can find a parts list online for that motor? I've seen one before, but don't recall where it was at. It is a 1982 Mercury 40 horse thunderbolt ignition.<br />Thanks a lot.

 

[jhreed]

Re: reverse lock on mercury outboard

Hey R8..., On my mercury, the mechanism was very stiff, as if the lubrication had gotten old and very dry... I physically moved the clawed teeth up and down (while in reverse of course) and the system loosened up and now works perfectly. Yes, I did get a heck of a surprise the first time I reversed also... We all learn from these little things, don't we? Jim Reed.

 

[rickdb1boat]

Re: reverse lock on mercury outboard

Don't know your serial number, but this link is what you're after. There is no gasket on the lower unit mating surfaces. If your motor is running good, then your plugs may just be fouling at low speed. You could try leaning out the low speed mixture a bit at a time and see how it does.<br /><br /> web page

 

[r8rfan]

Re: reverse lock on mercury outboard

Thanks a lot guys. I got her fixed! There is a plastic cam at the bottom of the shaft that was put in backwards. Turned it around and it now locks down in reverse. Had to adjust the shaft quite a bit as the cam is worn,but the parts list that Rick gave the site for has the part I need.<br />Thanks again for your help!

 

[arielgs]

Re: reverse lock on mercury outboard

Hi!
I bought an used Merc, 40 HP, year 2004 and the piece was broken.
I managed to make a new one usen steel, but i would like to see a picture to see if I am installing it the proper way.
Can somebody post a picture of the piece, pleeeaaaaseee?

Thanks in advance!!
:redface:

 

[hotrod53]

Re: reverse lock on mercury outboard

I have a '77 Merc 500 and it was missing a reverse lock rod. I found a NOS locking rod and I have the plastic guide as well as the top cast piece and the jam nut. I'm not sure where the plastic guide goes, on top or below the driveshaft extension piece, right side up or upside down, and I'm not real sure how that rod goes in or how to adjust it. I have the lower unit off and I'm ready to reassemble. That diagram that was talked about may be what I need...any help?

 

[Smurf]

Re: reverse lock on 1980 25h.p. Mariner outboard

Re: reverse lock on 1980 25h.p. Mariner outboard

I have the opposite problem on my +- 1983 25h.p. Mariner that when I put the motor in FWD the reverse lock does not release. Where is the adujustment for this?
Can anyone please help?

 

[hotrod53]

Re: reverse lock on mercury outboard

That is an indication that someone has improperly installed the reverse cam over the shift shaft. You will need to drop the lower unit and put the cam back into its proper orientation. The cam should be at its highest point when in reverse.

The cam fits over the splined shift shaft and can go back on in as many ways as the shaft has splines. It is very easy to put this back on incorrectly if not tested after the lower unit has been removed for an impeller change.

 

[carholme]

Re: reverse lock on mercury outboard

Smurf;

They do not like it when you answer posts that are that old. Ask me, I have done it many times.

Post a new thread, including your engine s/n and whether you have tiller or remote control. Your engine sounds like a mid 80s and it does not have a reverse lock cam.

Gerry

 

[Smurf]

Re: reverse lock on mercury outboard

Thanks for the reply, I will drop the lower unit and check as you advised.

Smurf