Impeller key question

[shelbert]

Hi since I started reading this site I have somehow become the family marine engine repair man. I am still trying to figure this out, but anyways.<br /><br />I have my brothers 1963 model 110 9.8 hp outboard in my garage for a yearly tune up. The problem I have run into is the impeller key is different than the one in the water pump kit I ordered. The lower unit and impeller was off when I received the motor, and the old key is no longer available. But the key in my manual shows a 1/4" or so slot in the shaft, while the 1963 has a round hole in the shaft for like a pin to go into. <br /><br />Is it possible to just manufacture a pin and if so out of what material should I make it. If it is not recommended can this single key be ordered seperatly.

 

[Mucka29]

Re: Impeller key question

Most older motors have a brass pin used to hold the impeller in place, just go to a hard ware store and get eather a brass or stainless steel pin and drill a hole on your impeller to make it work, use a small cotter pin to hold it in place

 

[corm]

Re: Impeller key question

you probably have the wrong impeller too, better check it. It should have a notch for the pin not a vertical slot. Use a ss pin.

 

[shelbert]

Re: Impeller key question

I went to the my local marine store and inquired about the impeller/pin. He told me the impeller was the right one even though it has a slot all the way up the inner shaft. He also told me the pin is superceded by a small metal flat piece with a ridge down the center.<br /><br />I am not sure what to think about that, the impeller is the physicaly right size as the old one. The old one did not have a hole in it or anything just a little groove at the bottom for the pin to go into. I do not see why the brass pin would not work in this case as well.

 

[Just Jed]

Re: Impeller key question

I had a Johnson 4hp that had a "T" key for the water pump impeller. The round pin fit the hole in the drive shaft and the flat "T" top fit the impeller like a regular woodruff key. Your Merc. may be similar???? Just a guess.

 

[shelbert]

Re: Impeller key question

Not sure what type of key I was suposed to use, so I made one out of a stainless steel pin. Needless to say the lower unit leaked air in a pressure test all over. I broke it all down and replaced all the seals and O rings, and in the meantime I went ahead and replaced the driveshaft with a newer one with the slot and it works great now.

 

[corm]

Re: Impeller key question

Hi,<br />Brass pins can shear off to easy Factory used a stainless steel pin, no tee. The original impeller had a notch cut in the brass sleeve for the horazontal pin to fit in to. The vertical slot is for the next generation of pump impellers. These fit on the shaft with a vertical pin. The last ones that they built use a 3rd generation key a half moon affair with a ridge running vertical on it that would lay flat in the shaft filling the newer style shaft than yours making it round with the ridge runnung vertical. The newer shafts all have a flat spot where the pin hole is on yours.