TOPIC:

Marc should be able to help on this, you might want to send him a PM to makes sure he sees it.

Update:

I think last I left off, I was waiting for outboard parts to arrive.  I ordered them from Joe Poole and while I said it once before, I would like to say it again, Joe was outstanding to work with.  Beyond expectations in all respects.  They don't make them like Joe anymore.

The parts came in last Tuesday and I installed them last weekend.  Parts included drive shaft seals, shift shaft seals, water pump housing and seals, impeller etc. All went in without much of a fight.  I am slow and deliberate since I have little experience with this.  I just did the seals in the top side of the LU so that could go back together.  Prop seals are questionable, but I did a hack-job pressure test and it seemed to hold. I used a bike pump while holding a hose against it at 12 PSI for about 3 minutes.  The needle didn't move.  I could redo this with a better set up, but that was what I has at the time.

I bolted the LU to the motor and tested shifting - Couldn't get it out of gear.  The shifter would not move.  I THINK I had the LU in Fwd and the motor's shift arm in Rev.  I had the motor's shift arm in the forward position and I think that is wrong.  I now think that is the Rev position. 
Am I correct on that?  Motor shift arm in the forward position is R, and in the aft position is F?

Tonight I pulled it off, verified F, N and R on the LU and then put the motor's shift arm in the aft position and tried it again.  This time I am able to shift into all 3 positions. R  (forward position) is a little harder to get into than the other 2, but it goes in with a little extra help.  Here's the issue that I see.  The reverse lock out hooks are not engaged all the way.  When in F, they are backed off as I read they should be, but the hooks should engage when in N and R.  I shift into N, and I see them move to engage, but they stop just before they engage... Maybe 3/8" from being fully engaged.  I shift into R and they move maybe 1/32" further but still not close to engaged.  I see nothing blocking them.  I am unsure if reverse lock out worked prior to me taking it apart.  My guess is that it did not, but I did not test it.  When in N and R, I can reach down and pull/rotate the hooks into the engaged position so there is nothing physically stopping them.  It's as if the R-lockout cam on the shift shaft is not raising high enough.

The manual and Google have been no help on this one.  I do not find anything suggesting a reason why the R-lockout is not fully engaged.

Before I take this thing apart again, does anyone have a suggestion on what I might have done wrong or where to focus?  I will look at the cam and see if there is a means to increase the cam height with rotation, but I thought I put that together correctly.

Thoughts anyone?

Thanks
 

I use 2-4-C grease all the time when putting a motor back together 

You may want to ask Mercury Marc. On both my lower units I added a dab of red rubber grease (made from castor oil) just to help with installation and prevent it from getting too hot. I like that product better because it does not deteriorate rubber like petrochemical grease might.

I also add a very light coating of red rubber grease to the rubber tubes that connect to the copper water feed pipes. I’ve seen a few of them that did not seat well. My thinking is that the grease helps with installation and can help seal that connection better. 

BTW, that is exactly how my cam looked when I installed it.

Question on the water pump housing gaskets.  There is no adhesive that goes on them, correct?  I should just clean both mating surfaces, then put the gasket in there dry and clamp down with the nuts.  Simple as that?


Assembly grease - any suggestions?  Merc says 2-4-C marine grease.  I'll get that unless there is consensus that something else works as good or better.

thanks

Thanks for the input everyone.  With your information and some reading in the manual and on the internet, it's becoming clearer to me.  I will know once I give it a shot.

Jpalin, the pictures in your manual are much clearer than mine.  Mine appears to have been photo copied from a poor photo copy.  I can barely make out what the pictures are showing, but I did read the process and it made sense.  I then googled a bit and found a thread on marine engine.com.  A guy had the same question on the same outboard.  There is a better description of what to do and a picture - attached here.
Link to the thread.

Not my Lower Unit


For anyone reading this later - the idea is that the brass cam sitting on the shift shaft (forward shaft sticking out of the LU) has 6 different potential positions it can be in around that shaft.  If it gets removed and you don't remember where it was, you have to put it back in the proper place otherwise your shifting and reverse lock out will be adversely impacted.  I will correct this if I determine I have it wrong, but with the motor in FWD and the LU(gear housing) in FWD gear, the cam needs to be in the position shown in that picture when you join the LU(gear housing) back to the drive shaft housing.  The 2 tabs that stick up from the cam should be in line with the threaded stud on the port side of the LU.  There are 6 splines so each spline would rotate the cam another 60 degrees.  Given that 60 degrees, the proper spline orientation should be obvious. 

My parts should arrive today so I will get after it soon as I can.  I will report back the progress.

Jpalin, your repairs look great.  You gotta be happy with how that turned out.  Depending on how things go, I may be doing something similar. I want to get it on the water first though.


Thanks again for all your help.  I think I will be able to do this.

That lower unit does not look a lot worse that what I had with my Mark75. Below are some pictures of my fix and final product.

Regarding the cam and leaving it in the correct gear: I make the mistake of charging my gears with the lower unit (Mark 55A) and eventually got my bottom shift cam misaligned. This happens when it is in forward and you rotate it again in the forward direction. You can’t fix it without taking the lower unit apart to reset the cam.

The manual is a little hard to understand how to alight the top cams, but once you figure it out it should work. Below are the pages out of the manual.

 
 

 
 
 
 
 

 

Now it’s 4 or 5 blades for a heavy load, or to make surf sized waves

Old rule of thumb was 2 blades for lighter loads and speed, three blades for more torque for heavier loads

The book has a picture showing you to line up the nubs with the stud, it's not clear but it works.

I think I have a lower unit sitting around and could take a picture for you.