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Lower Unit Help

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Rick1852

New member
Hello,

I have a Mercury , 2006 50hp ELPTEFI and just replaced the lower unit. Everything seemed to go together well but I think I screwed up something because when I have the control in neutral the prop is spinning like crazy. It seems to be in forward gear.
I don’t know how to change gears between forward, neutral or reverse on the lower unit to match the control arm in the boat. Can someone point me in the right direction? Thank you.
 
You didn't put the remote control shift lever in the same position as the shifter in the LU prior to installation. I like to use Neutral because there are gears on both sides in the LU telling you that you are where you think you are. The remote control end of it is self explanatory. You can see that the lever is centered.

Drop the LU down enough to get the shift shaft from the midsection to separate from the LU shifter splined stub. With a pair of pliers, grasp the stub while you have the other hand on the prop. Carefully move the stub in either direction until you can spin the prop freely. Once you think you are where you want to be, rotate the stub in one direction noting how the prop responds.....in gear, then back through N to the other side and note that the prop is affected in the other direction....then put the stub back in the N position where the prop spins freely.

Go to the remote control and center the lever. Reconnect the LU and you should be good to go......assuming the 2006 engine is setup like decades of Mercurys....I don't have nor had an '06 50 HP.

Caution: Forward gear has a sawtoothed connection to the drive line and it matters not when you slide the LU up into place. Reverse has vertical sided cogs and slots. Any time the engine isn't running or the crankshaft or the prop aren't turning, if the two don't line up and you force it you will bend your shift shaft or tear up something else. That's another reason why I like to use N when reinstalling the LU.
 
Texasmark said:
You didn't put the remote control shift lever in the same position as the shifter in the LU prior to installation. I like to use Neutral because there are gears on both sides in the LU telling you that you are where you think you are. The remote control end of it is self explanatory. You can see that the lever is centered.

Drop the LU down enough to get the shift shaft from the midsection to separate from the LU shifter splined stub. With a pair of pliers, grasp the stub while you have the other hand on the prop. Carefully move the stub in either direction until you can spin the prop freely. Once you think you are where you want to be, rotate the stub in one direction noting how the prop responds.....in gear, then back through N to the other side and note that the prop is affected in the other direction....then put the stub back in the N position where the prop spins freely.

Go to the remote control and center the lever. Reconnect the LU and you should be good to go......assuming the 2006 engine is setup like decades of Mercurys....I don't have nor had an '06 50 HP.

Caution: Forward gear has a sawtoothed connection to the drive line and it matters not when you slide the LU up into place. Reverse has vertical sided cogs and slots. Any time the engine isn't running or the crankshaft or the prop aren't turning, if the two don't line up and you force it you will bend your shift shaft or tear up something else. That's another reason why I like to use N when reinstalling the LU.
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Thank you ! I had read conflicting instructions on what gear to have it in when it was removed. Some said forward, some said reverse. What you say makes sense. Thanks for taking the time to respond.
 
Rick1852 said:
Thank you ! I had read conflicting instructions on what gear to have it in when it was removed. Some said forward, some said reverse. What you say makes sense. Thanks for taking the time to respond.
Click to expand...
Agree that some folks have their preferences as do I. I indicated why I chose N and since the cam can get turned around and you can be on one extremity and move it over thinking you are in N and you aren't you will have to go back in and correct your error. Hope you get it fixed and get back out on the water.

One of the reasons for some choices is moving the prop, close by, to see if you are in the right gear, or the flywheel which has to be exposed on some engines like mine. A plastic cover has to be removed to get at the FW but considering what I said above its "cheap insurance" that I get it right without question and is easily done.
 
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Texasmark said:
Agree that some folks have their preferences as do I. I indicated why I chose N and since the cam can get turned around and you can be on one extremity and move it over thinking you are in N and you aren't you will have to go back in and correct your error. Hope you get it fixed and get back out on the water.

One of the reasons for some choices is moving the prop, close by, to see if you are in the right gear, or the flywheel which has to be exposed on some engines like mine. A plastic cover has to be removed to get at the FW but considering what I said above its "cheap insurance" that I get it right without question and is easily done.
Click to expand...
Success! Everything went back together and is working correctly. Thanks again for your help.
 
I may have spoken to soon. After installing the new (used) lower unit I can’t get the water pump to work, not even a trickle coming out. Some of the things I have done so far, new impeller installed correctly, vanes facing the correct way, key in place so that the impeller rotates when I turn the shaft. I tried running with muffs but that didn’t work. I read that the impeller may have to be primed so I filled a large barrel with water deep enough to cover the impeller itself and most of the lower part of the motor and it still won’t work, nothing at all. I used compressed air to blow through the discharge port. I then took the lower unit completely off and ran a hose up through the tubing and the water came out the discharge port so there is no obstruction. I tried, as best I could, to watch that the impeller housing joined up with the tube on the inside of the motor but it is difficult to see. It looks like it is in the correct position at least until I lose sight of it.

I’m totally frustrated! I have done impellers on other, smaller, engines many times before and never had a problem. Is it possible that something is wrong with the lower unit itself that would cause this? Thanks in advance for any suggestions.
 
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