Quickie: Which Gearcase Oil For 1961 18HP Erude 15034?

Am meeting a good friend at the dock in a couple hours to see about helping him get his "new" 1961 Evinrude 18HP 15034 running - he just bought it and the previous owner said "it has 125# of compression and it ran great a couple years ago".

My friend is a little cramped for time to move his boat from where it is now to another marina and I'm trying to help make sure his engine is as ready as it can be for the trip.

We plan to inspect the impeller prior to attempting to start and run it. Then check the lower unit oil, then see if it will run or if it needs the usual carb work...

Any advice on the type of oil would be appreciated. Tried to search online but now hurriedly assembling the needed kit to get this done.

Also, any advice on particulars of removing lower to check impeller will be appreciated. I know the usual drill for 70s and 80s engines, but not so much on the older models that may have "special" tricks for the procedure. Any advice appreciated.

Will advise he purchase manual - any OB worth owning is worth buying a manual for IMO...

Any high viscosity outboard gear oil ( usually around sae 80W/90)

Youll have to disconnect the two parts of the shift rod ... (I guess accessible via the plate in the side of the exhaust housing) in order to drop the gear case to get at the pump.

Diagrams in the parts catalog may be useful http://www.marineengine.com/parts/v...evinrude-johnson/ITEM_2514/ITEM_251400001.htm

Thanks for advice.

Lower oil clean - looking fresh and good.

Impeller was not cracked, but had just taken a 'set'. New impeller was not available at usual OB parts supply. This AM we coated impeller with silicone grease and upon reassembly motor ran for a short while but then wouldn't restart. Compression seems good. No time to troubleshoot.

He'll use a different OB motor for this trip and he's putting this older OB on the back burner until after delivery of boat to new marina is complete. OB appears to have little to no wear on linkages and other items where wear usually occurs. Paint not even worn off prop much. Guessing its a very low hours engine, stored inside.