The 1/4 turn fasteners are called
DZUS fasteners. Look from them on airplane supply
companies. I have in my notes that the port side cover is part
number 1955740.

Put an ad in the free classifieds and I’m guessing someone will have
a carb bowl. Might as well make a gasket for it, and NOS ones
are likely shriveled up out of shape.

Those carbs have special rubber primer cups inside.
Following are my notes that touches on those and other things.
Good luck!

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Re: Evinrude 4423-32639 3.3 HP
Reply #1 – Apr 25th, 2011 at 7:47am Quote Touted in engineering circles as the outboard of the future, It was the first outboard in the world designed using CAD. (Computer Aided Design) Evinrude rented space on the University of Pennsylvania’s digital computer to design the carburetor. In had a lot of firsts. First top main ball bearing in a fishing motor. First outboard with a dual two stage rubber impeller water pump. First weedless drive with a ball pinion bearing. First outboard with built in tools. The screw driver in the tiller removes the quarter turn aircraft fasteners to expose the spark plug wrench and spare shear pins and cotter pin. The fine mesh filter under the carburetor will filter out water. The built in fuel gauge will show when it in time to add fuel. The mixture adjustment pointer on the front will pull up the float pin and close the air vent in the off position. The speed control shorts out the magneto in the stop position. The outboard should be stored with the speed control in the off position. This closes the air shutter over the third port keeping the moisture and bugs out of the powerhead.
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Although production started in the fall of 1947, the factory considered it a 1948 model. First models were rushed to florida to see if any bugs had slipped through engineering. Dealers were encouraged to sell it as Christmas Presents. It had a great many advanced features. Better gearcase seals let them put a ball bearing above the pinion gear. One of the first outboards to require oil for lubrication. The first non-racing OMC motor with a ball bearing top main. It was the first with a built in tool kit, the steering handle is a screw driver. (Copied by Mercury and carried over on the neutral clutch Fleetwin.) Evinrude rented time on the University of Pennsylvania’s ENIAC computer (Electronic Numerical Integrator and Computer) to design the carburetor. The computer’s development and construction lasted from 1943 to full operation at the end of 1945. The machine was huge, weighing 30 tons, using 200 kilowatts of electric power and contained over 18,000 vacuum tubes, 1,500 relays, and hundreds of thousands of resistors, capacitors, and inductors. One of the major engineering feats was to minimize tube burnout, which was a common problem at that time. The machine was in almost constant use for the next ten years. This amount of computing power is now contained in a cell phone … This was the first use of CAD (Computer Aided Design) in the outboard industry.
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If you have to change the prop and drive shaft seals, I just did my 4425 and 4423 Rudes and used SKF 5523 and 4770 seals. They aren’t snap in like the originals but with a bit of adhesive sealer they will work.
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Carb primer seals?
Micropoise and Andy

I picked up the cups today which I ordered a while back and have them installed in my Light Four. It took a bit of tweaking but I think there going to work. The 1/2" ones came with an 1/8" mounting hole already in them so I just had to turn about .060" off the pump shaft and the bottom pin to get them to lay flat. You could probably trim the seal slightly on the inside to get the same effect. When I had the pump all together I filled it with fuel mix and pumped it several times to prime it and it actually started pumping out the end of the little copper line! I’ll mount the carb back on and give it a try when the weather gets better. The place I got them from said the part number should ba a nation wide universal number so you should be able to pick them up or order them online no problem.

So Andy, the part number for the 1/2" nitrile seals is: AN6226-01 and as far as the 3/8" ones for Micropoise it’s 840300187. These 3/8" ones might be a little different style and material so you’ll have to check online before ordering. Good Luck!
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Andy wrote on Jan 13th, 2012 at 9:28pm:
Mumbles wrote on Jan 13th, 2012 at 3:33pm:

Where can i get carb primer cups for my 4423 evinrude? Carb was leaking badly from stem and further investigation showed forward cup failed and rear cup worn. The parts are 202119. considering making my own. any advice on how much over the .500 bore they should be? maybe .002 or .003 over? From the schematic I don’t see the need for cup shape. The bore is 3/8". I just made a drum shaped plunger that fits the bore good and stays on primer shaft. will try and test. I realize if not functional will be hard to start, but at least will not leak. submarines seemed alot easier to repair..haha.

Micropoise
I found a source for 1/2" cups yesterday and ordered a couple. As soon as I get them and try them out I’ll let you know. The same company here in town has a listing for 3/8" cups which should fit your 4423. Lets hope they work!

I need them for my Zephyr so please do let us know how they work.

Thanks,
Andy

Andy
The 1/2" cups I ordered are for the Zephyr or Light Four carbs with the 1/2" primer bore. I’ll let you know as soon as I get them if they work or not. It’s a shot in the dark!
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I took some carbs apart today and this is what I found. The Light Four and Zephyr both take the same cup, 201764. These are running in a 1/2" bore. The big Vacturi carb has a 5/8" primer bore with what looks like original leather cups. I’m starting to think there the same as used in GM carbs and sure hope so as that would be an easy fix. Your 4423 uses a 3/8" cup 202119? I’m going to try and source the 1/2" cups locally and will inquire about 3/8" ones. Will let you know later.