Honda Lower Unit

[corkscrew]

Ok, so I posted prior that I am having some issues with my engine (Honda 50 HP, 1999). Appears that the lower unit is having issues.

Synopsis:

Shifter broke as the remote would not put it in forward.
Replaced Shifter. All worked fine.
After a Day and full testing, Forward and Neutral Works Fine, Reverse does not work.
Goes into Reverse fine on remote, does not engage.
Rod seems to flex and does not move as much as Forward or neutral.
Out of water I notice if you spin propeller, in forward kind of locks and clicks dependent on how you spin...normal.
When shifted into reverse does not lock or click....light tapping as you spin propeller.

My mechanic says the lower unit either has a gear problem or there is something stuck or not engaging.

Anyway, I am going to pull off the lower unit tomorrow and look at it a bit more. Wondering....has anyone every rebuilt these? Ever, replaced the gears? What could be my issue?>

He is recommending simply replacing the unit....$1200. I expect I could also rebuilt this or have someone do it.

Any thoughts would be great......PS if anyone has a used, but working, lower unit I may be interested.

[Frank C]

Well, one word of warning. When I removed mine for replacing the impeller, I had enormous difficulty with the stainless bolts that connect the drive to the power head. They are tapped into the aluminum casting, and prone to corrosion-freeze. If you strip any of them, you'll definitely be considering replacement of the power head, or expensive machining work. This is one reason I finally elected to just "pay to freight" for a pro to open it the second time. If they break it, they fix it. I suggest asking permission to "watch 'n learn" but many times they'll just say "NO."

[bill barchard]

The honda lower unit is the same as a mercury 50.

[opie]

I have previously posted some pics about a corrosion problem. In removing the lower unit, it is easy IF (really - "IF") the bolts have been removed in the past 12 months and replaced with anti-seize on them. That being said, the shifter rod from the lower unit is connected with two small nuts to the rod from the upper unit. To test your problem, remove the lower unit and operate the propeller while raising and lowering the lower shift rod manually. (I can not remember if it is "up" for reverse or "down" for reverse. If you get neutral in the middle position and reverse and forward in the opposite positions and no clicking as you described, then the lower unit is fine. Your problem is in the amount of connection length in the shifting rod. If problems persist with the lower unit off the power head, then you do have gear problems. Even then, I would remove the propeller first and clean out the spaces behind it. Maybe some shell or fishing line is caught in there. If bolts won't turn, soak them twice a day for a few days with a solvent. If there IS a gear problem, then from what I learned from the shop manual, you need special tools to take it apart. My guess is that you have a shift rod connection issue. Or, the remote control unit is not moving the rod far enough up or down to fully engage the gears. Removing the lower unit will give you the anser you need.

[socalmacer]

I've been removing my lower end unit for years and found by dipping the bolts in some marine grade grease prior to reassembly I've managed to avoid any corrosion or sezing problems. Prior to doing this I had a problem with one bolt stripping out where the end unit actually developed a slight crack where one of the bolts threaded into. I used JB weld to repair/strengthen this area and haven't had a problem since. I can even torque the bolt to spec.

I agree with the above about the getting the right length on the shift rod is key to shifting. The first time a disassembled I didn't mark the engagement and needed to adjust until the shifting was right. You might consider bench testing your lower unit to see If you can get the gears to turn in different directions with settings of the shift rod.

Good luck...these are great motors anyways!!!

[corkscrew]

hMM, LOTS of food for thought.

Like I said....neutral spins fine. If I put into forward.....it locks (becomes tight) one direction and clicks if you spin it the opposite. So I am using this as a baseline as how it should behave and sound working properlly. When I put it into reverse, the bar does not seem to move very far Down..(as it does when I fo UP - forward) - seems like it does not reall click into gear like in forward. and you hear lights clicking when spinning the properller...but not like in forward....so I assume its just barley connectin g with the gears.

Now...in the back,....the rod comes down...in the upper part there is a small nut with a larger nut on top (actuall on the rod) and then under it the rod has sort of an elbow bend in it. Where do I adjust the length of the rod?

[corkscrew]

PS....does anyone have a digital schematic or repair guide of the honda bf 50 late 90's? they could email me?