Designing Muff for 6hp Johnnyrude

[CATransplant]

OK, I'm working on a design for a device that will attach to my 1992 Johnson 6hp that will allow a hose connection. It won't be difficult for that engine, and I plan to post drawings and instructions for others to make one, as well.

But...I have a question for owners of 6hp motors from the 60s, 70s, and 80s:

On the '92, the intake screen in the water outlet tubing extends up past the cavitation plate, and there's another opening above the plate that can also allow water in to the cooling system.

Is this true on the earlier 6hp models? If you have one, please take a look at it and let me know. Also, what is the length of the long side of that water intake and exit tube on your outboard, from the cavitation plate to the tip of the tube.

If possible, I'd like to design this to be useful on multiple models. If they all have an intake above the plate, as well as below the plate, I can design it so that the device blocks the lower intake and puts the water in the upper. If not, I'll design it the other way, putting the water in the lower intake.

Finally, if you can snap a photo of the upper intake, if it exists on your earlier model, it will help me with the design.

I may sell these, but I'm going to give away the design drawings and instructions here, so thanks for all your help. Sadly, the parts diagrams on the BRP site aren't detailed enough for me to see this. The later models use a combination screen and plug, while the older ones have a separate plug, and I can't see the correct side of the housing.

 

[ezeke]

Re: Designing Muff for 6hp Johnnyrude

It is true that the water inlets are above and below the a/v plate on the earlier models, including the 1965 which I own. The upper entry was to let water in when in reverse. When the propeller is turning, it forces water into the screened lower entry. If you put an attachment on the lower entry, you have to cover the upper one.

I have one of the tempo flush kits but it scratches paint, the propeller can't turn and a five gallon bucket does the job perfectly.

 

[CATransplant]

Re: Designing Muff for 6hp Johnnyrude

Cool. That simplifies matters. I can simply have my unit block the lower intake screen and feed water into the top opening. The way it currently looks, you'll be able to even put the outboard in gear to check shifting while connected to the hose.

On your '65, is the bottom of the upper inlet pretty much even with the top of the plate, as on my '92? What is the height of the opening. I don't care about the shape. Oh, yes...I'm assuming the upper inlet is on just one side of the leg, too, as it is on the later models...right?

While you're right that a bucket works, it'd be pretty nice sometimes to be able to use a hose, instead.

One thing I guarantee is that my device won't scratch your paint.

 

[CATransplant]

Re: Designing Muff for 6hp Johnnyrude

OK, I missed your photo, which answers most of my questions. That Tempo dealie is a kludge, for sure. I'd never seen one. I can do much, much better than that, I think.