Johnson A25 operating noise

[JONATHAN C. SMITH]

I have a 1925 Johnson A25.  It runs quite well, starts right up.  I have noticed that after running for about 10 minutes or so I start to hear a whirring noise, that does not seem to come from the power head.  I use the recommended oil mix of TCW 1/2 pint to a gallon of gas and no apparent problems, no knocking, no over heating.  I wonder if the noise could be coming from the lower unit or the water pump.  I regularly take the lower unit apart at the end of the season to drain out collected water, and change out the John Deere corn head grease.  I note very little lateral play in the prop shaft, and almost no perceptable end play in the prop shaft.  There is considerable wear on the gear teeth, with pitting noted on the pinion gear teeth and the prop shaft gear.  There is about one inch of gear lash as measured at the outer circumference of the  propellar.  So is this noise “normal” for an hundred year old outboard motor?  Anything I should be doing differently, or adjustments that need to be made in the lower unit?  Thanks Jonathan

[Tubs]

Your measurements sound good to me. Gears are worn in now. If something needed to be tightened up a little it would likely make the whine louder. I’ve have, and have had, a fair amount of 20’s & 30’s motors and I’m able to leave a motor on for weeks at a time. As the grease is replaced with water, the whine gets louder. I can tell when its time to be adding more grease. This is normal for this motor and its 30 years newer. Video Link – https://youtu.be/N-Hsh57stUw

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

[JONATHAN C. SMITH]

Thank you for the information.   Several years ago I think you sent me a picture of the lower gear case parts for the A25 laid out in order of assembly.  I cannot find that picture, not sure where I saved it to.  Any chance you might still have that and could send it to me again?  Jonathan

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