Help identifying missing parts on Johnson 4HP 1978 (Model 4W78E)

[JSPG]

Hi everyone,


I'm reaching out to ask for help regarding my 1978 Johnson 4HP outboard (model 4W78E).


I used this motor regularly until around 15 years ago, when the drive pin broke during use. I stored the motor away in a shed and haven’t used it since. Unfortunately, I’ve now realized that the propeller is missing, and I’m in the process of restoring the motor.


Looking at the parts diagrams, I’m unsure which components I actually need to complete the lower unit. The prop shaft is still in place, but I don’t know if all I need is a new propeller, drive pin, and cotter pin, or if the prop requires additional bushings or inserts that need to be purchased separately.


If anyone here has experience with this specific model (4W78E), I’d really appreciate any guidance on:

• What parts come with a replacement propeller (OMC 0319004 or compatible)
• Whether any internal bushing or hardware must be installed separately
• Any photos showing a fully assembled propeller setup on this motor

Thanks in advance for your time and help.
I’d love to get this motor running again and pass it down to my son as a family legacy project.


Best regards,
Juan

 

[JSPG]

I'm not very familiar with the older "weedless" pin-drive propeller system, and while looking at parts diagrams, I’m trying to figure out exactly what I need to order to restore the propeller assembly.


So far, it looks like I'm missing:

• The propeller (likely part number 0319004)
• The drive pin
• The cotter pin or locking washer

What I’m unsure about is:

• Does the propeller include any internal bushings, inserts or o-rings?
• Are there separate seals or spacers I should order to complete the prop installation?
• Is there any chance the bushing is part of the shaft and not the prop?

The propeller shaft is intact, and everything else on the lower unit seems fine.


For context, I’ve already ordered:

• The OEM carb kit
• A new impeller
• Fuel pump
• Spark plugs
• I’ve also tested compression and spark, and both cylinders check out fine.

I'd really appreciate it if someone familiar with this specific model or similar pin-drive setups could confirm what parts I absolutely need to get the propeller fully functional again.


Thanks in advance for your help!


Best regards