Can't Get LU to drop down on 1976 15Hp Evinrude

[OptsyEagle]

So I am in the process of changing the impeller on my outboard. I have the 6 bolts off on the LU and I have removed the top screw on the shift rod. The LU does not want to drop down completely. It is in the 1/2 inch down position. The shift rod moves out of the connector when I move the shifter so that is not snagging. I have turned the flywheel a little as well as the propeller and still it does not drop down.

Am I missing something?

 

[racerone]

You need to use a bit more force, that is all that will be needed.

 

[OptsyEagle]

Thank you. More force got it down.

Now I am having another concern. Do the splines on this drive shaft look normal. The outer splines seem to have a well defined machined line on one side and then becomes jagged on the other side. All 4 outer splines seem to be like this. I would have thought they would have been well defined on both outer edges of all 4 splines but I am not sure. Perhaps this was why it was so difficult to drop down. It is also making it difficult to remove the impeller or put a new one on.

 

[racerone]

Very , very obvious to me what is wrong here.----O-ring at the top was left out and no grease on the splines.-----So now you need to remove power head to inspect the crankshaft spline.------Rust is very abrasive and similar damage was done in the crankshaft spline !-----Not to worry as used cranks are easy to find.

 

[OptsyEagle]

The was an O-ring on there that I removed before I took the pictures. As for grease, I think I used marine grease (used on propeller shafts) on those splines the last time I changed an impeller. I did not have any moly lube. Would that make a difference?

 

[JohnnyGuy]

The was an O-ring on there that I removed before I took the pictures. As for grease, I think I used marine grease (used on propeller shafts) on those splines the last time I changed an impeller. I did not have any moly lube. Would that make a difference?

Marine grease would be fine. I use a thin layer of the BRP triple guard grease when I redo these. You just don't want to allow water into the splines between the driveshaft and the crank.
The o-ring should keep the water out and the grease provides that additional protection and stops corrosion.

 

[OptsyEagle]

The drive shaft might have been like that the last time I changed the impeller. I might not have noticed it. I do have a parts motor (1975 9.9Hp) so I will look at that drive shaft. I imagine it should be OK but we will have to see. I guess I should remove the 15Hp powerhead and look at the crankshaft splines. They must be messed up as well. Would it be much of a job to remove the 9.9Hp crankshaft splines and put it on this 15 Hp powerhead once both PH's are removed. The 15Hp has new upper water grommets, rebuilt fuel pump and probably a few other items that I would prefer to retain. It also goes faster.

 

[racerone]

The complete 9.9 crankshaft would have to swapped over.

 

[OptsyEagle]

I was afraid of that. Well I will take a look at the crankshaft splines on the 15Hp and maybe they will look OK. If not, I will probably switch the entire 9.9Hp powerhead over to the 15 and then switch the carburetors and hopefully end up with a good motor. The 9.9Hp does not have any upper motor mounts left and its carb is corrupt. If it wasn't for all that I would just switch the carb and save myself a lot of trouble.

Thanks for the help. Really appreciate it.

 

[oldboat1]

Opsy -- pics are almost too good these days, can't tell what's serious damage, and what isn't. I would try cleaning up the shaft splines with some solvent and some scraping. That type of spline might be less subject to damage, so might be usable. Think with a good light and a pick or two, you should be able to get clear about the condition of the engine splines.

Some marine grease, avoiding the top of the shaft, and may be good to go.

 

[OptsyEagle]

The motor was working fine when I put it into the shed about 3 years ago. As I said, the shaft was probably like that when I changed the impeller the last time, 8 or so years ago. I will at least look at the driveshaft on the other motor to see if it is in better shape, since that is what that parts motor is for. I have to remember that these motors are over 45 years old. I know they last forever but they certainly do degrade. It's not like they don't have other, perhaps not catastrophic, but still annoying issues. That said the motor I have been using in the last couple years is 60 years old, but runs better then the rest I have.

No wonder OMC went bankrupt. Waiting 45 or more years for your customers to replace their products would probably put any company out of business. lol

 

[racerone]

Market conditions changed.------Some folks now realize how good these 9.9 / 15 HP 2 stroke motors are.---- But the general public loves to spend money on the 4 stroke motors.----And spend plenty doing so.