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Interesting and very timely thread for me; since I recently acquired a KB4. My lower unit does not have that notch in it like the one pictured above. Maybe after 79 years I should take a round file to it?
Tough getting the shear-pin out otherwise; I’m puzzled as to how they got it in!
Chuck
Chuck,
That must be the navy motor?I would pry up gently on one end and tap the other end with a drift……gently. Hard to say after 70+ years if the PO put the correct length shear pin in there. It’s 3/16 so it’s easy to make one if you destroy that one while removing.
On the other hand, I don’t see how it could hurt if you wanted to file a nice clean recess in the edge to help with the removal.
I don’t recall too much difficulty in removing them. It’s the pin in the eccentric cam that has proven more challenging to me.
Good luck and keep us posted!
Scott
Guys,
I would not modify a Navy motor or any 16 square hole intake housing. (To Rare!)
I would press pin out of gear using a simple jig on small arbor press.
That way you can remove the steel eccentric cam to replace shaft seal or packing.
(See first picture.)(Second picture) is a 1941 oscillator style pump from my 1941 Wizard WB-3 showing
The brass eccentric and drive pin retainer.Good luck,
Bob
“Is that spring holding the eccentric cam pin really necessary? Where could it go? Also, I don’t see the spring in the charts Bob posted in the tech section.”
The eccentric drive pin would fall out behind prop and motor would overheat due to drive pin failure! (Clip is important!) VERY
Bob,
Now I’m confused. In neither my sea king (K1) nor the K3 tear downs did I see any of the parts you mention. Not saying they’re not there, I just may not be seeing them. You say if the steel cam is removed, it allows you to replace the “shaft seal or packing”. Are those two the same thing? I see prop shaft packing (#63) and prop shaft packing cup (#64A). Can you post pictures of those parts or point them out? Is one of them that copper colored sleeve covering the pump housing bushing in your picture? Looks like it has a crack in it? Can you explain how those parts are installed? And where?Another question. I also did not see in either tear down that retaining ring you point out (#53-24433). In the brass cam I see a groove for it but the steel ones have no groove. I assume that’s where that ring goes?
Also, the spring I was referencing above is the one in this picture. I don’t think this particular spring is a stock item, is it?
Thanks and sorry for all the confusion. I am new to these gear cases but would really like to understand them.
Scott
It helps to round off the sharp edge of each end of the pin. It may also
help to reduce length by a tad. Smoothing pin over its length with abrasive paper may also help. Pins do get bent ever so slightly and
become difficult to remove or reuse.
I believe prewar KB4 twin would have had the 7 slit water pump and
the 3 element clutch with one pin. If run without the clutch with the
propeller directly engaging the sheer pin, there is need for a short pin
to drive eccentric cam PLUS a spring clip in the groove to retain the
drive pin.
Length of sheer pin or clutch drive pin can be gauged by
length of slots in propeller or metal clutch disc
Length of oscillator drive pin (for 7 slit version of oscillator cam) is diameter over pin hole less twice depth of groove.
Hope this is clear enough to follow.
LouisIs the spring needed. I believe so, remember the eccentric cam on 16 square hole type water pump has a hidden pin which is installed when the cam is not fully seated..With the pin in place, it engages the slot in the cam, but, is clear of the cam at the other end, the cam then can be
pressed down ,closing off the pin from the holes in cam. The spring
installed on prop shaft between sheer pin and face of cam serves to
keep cam from moving up shaft and possibly allowing the cam drive
pin out.
The grease seal packing is formed inside base of eccentric
cam…so far as I know no packing cup with the 16 square hole.I have found making a pin that will fit and function involves a lot of file
and try, file and try,tile and try. Approximate length is diameter of shaft
1/2″ plus depth of slot 1/16″The 16 square hole and 7 slit oscillator type water pumps share some
parts and there is some swapping possible.
The 7 slit seems to have the packing in a cup grease seal. I have not seen it on the earlier pumps. Like all small parts on old outboards
sometimes they wandered off while being serviced.The 3 slit casting water pump is the only one where a vane was originally installed. I do not believe the vane impeller will physically
fit due to the raised ledge, or it the ledge is removed the intakes may
not be clocked in right position for vane to work.Leather seals…ALL models of the Early K Model from K1 to WG4 came with a leather or raw hide lower drive shaft seal. I have even
found one or two still in decent shape. I reinvented the wheel to devise
a method to make leather seals. A small item that was in the back of my mind for years, that came to me in minutes from idea to finished
seal.
I will make photos and share.
Louis
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