Evinrude 1957 5.5 HP Gear Case Questions

[mondobug]

So I decided to rebuild the carb, replace the impeller and most of the seals and o-rings including the prop shaft seal. Just doing some cleaning and scraping while waiting for the parts. The gear case was so full of thickened, gelatinous goo that I didn’t notice how this was installed:

The gear case head/bearing has a tab which seems to fit in any position – but seems to fit better (and the gears may be a bit freer) pointing down (from where it’s shown in the picture) into a recess in the casting – or up, into to skep half of the housing which also has a recess. So is there a correct position for the tab and which is it?

The clutch sliding shifter. I lost track of which side was facing where. The dogs on this part have a just a bit of wear, with the edges very slightly rounded. One side has a bit more wear, while the other side is nearly perfect. Is this part reversible? Perhaps to use the better side for forward gear? For that, would it be engaging the gear at the right side of the photo, opposite the prop? Good idea?

Thanks for any help!

[Mumbles]

You got it. The tab faces down into the gearcase when it is upside down while working on it. It’s the wrong way in your picture. The dog is reversible and yeah, install it with the best teeth facing forwards into the forward gear.

[mondobug]

Thanks Mumbles! This helps a lot. I have another question. I received the parts. The intention is to replace all of the rubber parts but the upper grommet for the water tube looks tricky to get just right. Any tips to make this an easy process? The tube is still attached and the connection looks OK. Should I just leave it alone? Opinions anyone?
Thanks again!

[david-bartlett]

Mondo,

That upper grommet is not as bad a job as it might seem. Some long needle-nose pliers, or a piece of threaded rod with a nut on it to push against the grommet will do it. Just get the tabs on the new grommet lined up with the holes in the gearcase, and use a little grease. Nothing to it.

[mondobug]

I want to thank every for the help. All work went well and the end is in sight. Lower unit serviced and installed. Carb rebuilt and conversion for fuel pump done. I replaced the coils and wires some years ago so the magneto checks out. Someone gave me a good single line tank to replace my extremely rusty pressure tank. Just waiting for a new prop. The old prop may have had a week spot as a blade broke off in my hand. I’m excited to use the motor again. Just some final questions please:

The roll pin at the top of the drive shaft (for the shaft to crankcase seal) was half gone, I assumed it rusted through. I replaced it with one I had on hand but now I’m concerned that the OMC part may be stainless? Is it? Will the steel pin be OK for a few years if so? I would have to drop the lower unit to change it again.

The powerhead bas gasket. Do you guys use gasket sealer on both sides of the gasket – or leave one side unsealed for easy powerhead removal?

I bought a 3/8" (7 feet long) fuel line for the tank because there were more choices than anything smaller. Will there be any issues with the Mikuni pump’s ability to pump that kind of volume?

Thanks again !!!

[crosbyman]

Mikuni pump should be ok as it is more an issue of lift rather than "pull" the gas from the tank. the bigger the difference in height the harder it is l
to lift the gas .

Joining AOMCI has priviledges 🙂

[fleetwin]

I would definitely pull that powerhead and install the OEM roll pin, which is probably stainless, replace the oring and gasket as well. Once everything is in order, go ahead and coat both sides of a new base gasket with sealer to avoid any pesky leaks.

[mondobug]

quote crosbyman:

Mikuni pump should be ok as it is more an issue of lift rather than “pull” the gas from the tank. the bigger the difference in height the harder it is l
to lift the gas .

Thanks. This helps.

[mondobug]

quote fleetwin:

I would definitely pull that powerhead and install the OEM roll pin, which is probably stainless, replace the oring and gasket as well. Once everything is in order, go ahead and coat both sides of a new base gasket with sealer to avoid any pesky leaks.

I have new a drive shaft o-ring and seal but I don’t have to remove the powerhead (its not installed yet) -just drop the lower unit to get at that roll pin. I asked the supplier if he knew if the OEM pin was stainless when I ordered the other parts. He didn’t know and the thing was like 6 bucks. I figured that since the original was half rusted away, it might not be stainless so I just used a pin that I had around.

Thanks. I’ll order the OEM pin or get a 3/32 x 5/8 stainless roll pin from a fastener supplier. Getting what was left of the old pin out without doing any damage was one of the worst parts of the whole job but removing the new pin I installed shouldn’t be so bad.

[mondobug]

So I found out that the OEM pin that concerned me is just a 3/32 x 11/16 roll pin but it is stainless. I get a discount at the local Fastenal – my cost is 4 cents each but I had to take 3/4" long stainless pins which shouldn’t be a problem. They’ll be in Friday- No shipping charge, the guy just basically sampled me a half dozen. Base gasket is secured so at this this point the only small loose parts I have left are for the drive shaft upper seal-and some screws, at least until Friday night when I’ll have to drop the lower unit again to re-do the pin.

This motor has always been a good match for my boat, a 1960’s or early 70’s aluminum semi-v Smokercraft that I spruced up last year and fitted a new varnished Teak transom board. It’s not quite 12 feet long and narrow of beam so it’s very light and this little motor pushes it along at a good clip. So when I get the prop – and if the motor runs well, I’ll be excited to get back on the water!

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