1962 Evinrude 40hp Lower Unit Leak?

[justin4530]

Hey all,

I fixed up a 1962 Evinrude lark 40hp 35933L electric shift, brought it down to the slip and got it idling and running nice. However, it slicked the water pretty good and was leaking when I pulled it out. I know these old two strokes are dirty, but this seems like more than spent gas and oil to me. I'm guessing maybe a leak in the lower unit somewhere. I previously pulled the lower unit to replace the impeller and found a small amount of water in the old oil, but it held 10psi for 5 minutes when I tested it. When addressing a lower unit leak which seals should be replaced?

Thanks for any input

 

[Crosbyman]

first it held pressure so next is a vacum test...... but i would not rush a seal job if you recheck gear oil for water ingress ... keep the oil and put back in the GC if not contaminated.

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old engine do dump oil/fuel in the water when excess is collected in the crankcase due to much idling... give it a good wot shot

 

[justin4530]

Thanks for the input, thinking back on it I was idling it for a long time messing around with the adjustments and letting it get up to temp, ill double check for water in the gear case and go from there.

As a side note is type C gear oil available anymore? or is there a modern equivalent that works with the old electric shift

 

[racerone]

Type C is available.----Or ask for the Sierra equivalent.----Pulling a vacuum on single lip seals may not prove anything.-----If water was in the gear oil it needs all new seals.

 

[jimmbo]

BRP markets the Oil now as Precision Blend.
Beware though that there are a few Brands on the Market that claim to be Type C, but are not compatible with the Electric Shift.

You have used new Washers on the Drain/Fill and Vent Screws, every time you replace them? They have been known to leak small amounts when used again.
As for which Seals, are prone to leak, the ones below the Water Pump can allow the Water Pump to push water into the Gearcase. The Propshaft Seals can also wear, but they are often damaged by Fishing Line.
When pressure or vacuum testing the case, it never hurts to rotate the Driveshaft and Propshaft, to see if that disturbs the Sealing

 

[Mc Tool]

All the above ....and it doesnt take much blue smoke oil out the exhaust to slick up the water if your not on the move....gets obvious real quick .
Good on you for resurrecting another old gem .