Year of Manufacture and Diagrams Needed

[frankr]

That off-center drive shaft should be a clue—whatever it is. Normally I’d say a bent gearcase or bent exhaust housing. That may be the cause of all the other woes also. You’ll have to check it all out when you get it apart. With the 3 screws out, the gearcase cap should slide off with ease. Nothing touches it except the front bearing and shift rod slotted nut.

[Buccaneer]

I was just thinking about the drive shaft being way over to the side of the tube,
and was thinking perhaps the drive shaft sleeve and spring is out of place
or messed up. Will try looking down the rabbit hole again.
Regarding the gearcase cap sliding of with ease……. I’ll tell it you
said that when I get back to the garage, lol.
Thanks, Buccaneer

Prepare to be boarded!

[jim-moffatt]

It is a 1950 Firestone 5 hp. To decipher the 5017: 50 means made in 1950, 1 means it has a Firestone badge and 7 means its a 5 hp.

Why it ended up 7 is as follows. The first 3.5 hp models were designated 1 0r 2 depending on trim level. The next motor put in production was the 7.5 hp and it was designated model 3. Then in 1950 or so they introduced the 5 and 10 hp models. The 5 hp has designation 7 and the 10 hp has designation 8.
It is confusing!

[phil-b]

quote Jim Moffatt:

… To decipher the 5017: 50 means made in 1950 …

How odd! They didn’t reverse the digits in the year!! 😉

[jim-moffatt]

The drive shaft has a spring midway down. Quite often the whole spring is bent or broken. Thats why its off center.

When you pull the front cover of the gearcase it should come right off with the prop shaft still inside the case.

If it doesnt first make sure the shift fork is free from the shift rod. Test by prying in the opening available. Then if it is still stuck remove the propeller and pin and pull the whole shaft out with the front cover.

[Buccaneer]

Thanks for deciphering the numbers! I only knew it was either 1950, 51, 52, or 53.
I have most everything apart now. I "think" Frank may be correct about having
a bent lower housing. If I’m not halucinating, it may be bent about 6" above
the gear case. I see no evidence of damage on the outside….. how is it possible
to bend a lower unit "sideways"? If so, anyone have luck straightening them out?

I’m not seeing a spring on the drive shaft that could be "out of align". Inside the
aluminum tube there’s a tang which slides into the lower stub shaft…… unless
the tang is part of the spring?

The lower drive shaft, stub shaft was froze. Some WD-39-1/2 and one whack
and it was loose. The prop shaft was froze, from rusty and crusty needle and
ball bearings. The prop shaft and gears are not pitted though, and it should
be in good shape with new bearings. It appears that there being absolutely
no oil in the gear case, and rusty crud, was the result of someone deciding
to use no gasket, but blue silicone instead!

In the gear case front cover, what’s the coned shaped brass piece’s job?

Photos below…..
Upper Drive Shaft
http://www.grayhitandmiss.com/Outboards/dscn4900.jpg

Lower Unit, bent?
http://www.grayhitandmiss.com/Outboards/dscn4894.jpg

Gear Case Front Cover, etc.
http://www.grayhitandmiss.com/Outboards/dscn4897.jpg

Gear Case with Drive Shaft Stub shaft
http://www.grayhitandmiss.com/Outboards/dscn4899.jpg

Prepare to be boarded!

[frankr]

What will bend a housing you ask? Well several things. Boat moored with lower unit stuck in the mud and waves tossing it around. Launching the boat off a trailer with motor down and shallow ramp. Rear ended by a car on the trailer. These are just a few. I’m sure people have come up with some more creative ways.

[Buccaneer]

Okay, now that we know how to bend a lower unit, do we know
how to "un-bend" a unit 🙂
Seeing how there’s no external visible damage, I like your idea
about it being stuck in the mud while moored!

Prepare to be boarded!

[jim-moffatt]

The spring is flat and goes from the top drive shaft to the lower stub. At the end it looks like a tang.
The brass cone provides the detent for the gearshift. It rides against a flat shaped cam with indents in it.
The shift works by the cam pushing on the pin in the center of the prop shaft.
Proper operation of the shift requires a gearcase gasket of original thickness so sealer alone will not work well.

[johnyrude200]

This is the type of document we should be adding to a digital library that is searchable based on part #. Even with this resolution, it should be text-recognizable.

Gary, Frank R, Jim M, and many others, you continue to post pictures and helpful reference info for all of us. Some day this may not be possible. We should think ahead about this topic and be proactive about it now.

[Author]

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