impeller key 73 evinrude 40 hp

[dserwin]

In an attempt to help a friend replace a impeller on a boat that is new to him, we ordered a new impeller, removed the gear case and pump housing, but found the impeller key missing--no problem we can get a new one.
Upon closer inspection, the drive shaft does not have a slot for a woodruff key as I expected, it has a round hole drilled where the key should be. The picture of the key on the parts diagrams shows a woodruff type key. I have not ordered a key yet, but it don't seem like it will work--what am I missing here? I don't understand.
Thanks
attached is a picture

 

[racerone]

It appears the motor has an older driveshaft installed in it.----Perhaps the entire lower unit was swapped with an older lower unit.-------Just order or fit a stainless pin for it.---------Or find the correct driveshaft.--Should be lots of them around.

 

[racerone]

They went back to the older style lower units on the 40 hp in the early 70's------I have seen the wood ruff key modified to fit the narrower impellers too.------Ends were machined down.

 

[hardwater fisherman]

No Title

This is what I used in my 1976 40hp evinrude that has the same hole in the driveshaft. I searched a little bit and it seems they switched to this style in 1972. Part number 0317078. Sorry it appears to be 1971 when they changed the style of keys.

 

[hardwater fisherman]

No Title

This is what the earlier style looked like.

 

[F_R]

The round key (pin) for the shaft you have is part number 300771

 

[hardwater fisherman]

Shopevinrude.com lists 0317078 as the key for a 1973 40 hp.EDIT My 9.5 uses that pin. I am not saying it wont work with that pin but I know the key 0317078 is the key that was in mine when I changed my impeller and I have used it for 2 seasons without any problems. I could be wrong but from what I saw at the BRP website it shows that pin being used from 9.5 hp to 25 hp. And the other type for the 40hp.

 

[hardwater fisherman]

I also have a 1975 40hp Johnson that I use for parts and it also has the key type 0317078 and not the pin.

 

[dserwin]

It seems that I have a older shaft on this motor. The key (0317078) will not fit the shaft-it has a round hole for a pin. So will this pin (300771) work with the impeller for the 73 model or will I need to get a different impeller?
What years did they use the pin type shaft?
Thanks for all the responses

 

[hardwater fisherman]

I was wrong it is my 1963 28hp that has the round hole for the pin. I just glanced at my parts and thought it was my 40hp. But also I looked and all the way back to 1960 the 40hp never used that pin. Maybe you have a drive shaft from something other than a 40hp. Just buy the pin and you should be good to go.

 

[racerone]

Post # 2 indicates that it may have a different lower unit / shaft installed.----40 hp Gale or 33 hp Johnson / Evinrude come to mind.---The 40 hp Johnson from 1960 to 1970 used a wider impeller with the woodruff key

 

[F_R]

It seems that I have a older shaft on this motor. The key (0317078) will not fit the shaft-it has a round hole for a pin. So will this pin (300771) work with the impeller for the 73 model or will I need to get a different impeller?
What years did they use the pin type shaft?
Thanks for all the responses

What you have there is a shaft that came out of a 33hp (probably). Or a Gale. Or a pre-1958 35hp. Actually, similar shafts were used in lots of applications. Doesn't matter, the 300771 pin is what you want, and yes it takes the same impeller.