Impeller Pin/Key

[B_Well4200]

I have a 1966 mercury 9.8 hp. Serial #1876179. I am trying to get the impeller locked in to the drive shaft. In all the diagrams I have seen for these year models it shows a key but there is no slot or grove for an key on the drive shaft. Instead it looks like there WAS a pin there. If have read through some threads and I have seen no mention of a pin instead of a key locking in the impeller. I was wondering if it was a pin to lock it in where / how can I get another. Thanks in advance for any help.

 

[Texasmark]

Re: Impeller Pin/Key

I read that around that time, when the colors changed and the sloping drive line....fisherman I think they called it, thru prop was introduced and all, funny things were going on with the lower unit and all. Later on, I know for sure in 1974 they had a flat slot cut in the drive shaft and a brass insert was slid in there with a dimple on top of it which fit a cutout in the impeller brass sleeve for at least the 7 1/2 I had and the 9.8 a neighbor had. I bet your local Merc dealer could help or give "Faztbullet" a ding on this site. He ought to be able to help you find one.

HTH,
Mark

 

[racerone]

Re: Impeller Pin/Key

Is there a hole in the shaft or just a flat area ?-----------Is it the original lower unit or possibly a newer replacement ?---------Pictures always help.

 

[B_Well4200]

Re: Impeller Pin/Key

There is no flat area on the shaft for a key. There is a hole. As far as I know it is original but I don't know for sure. I will post pictures as soon as I get home and figure out how to post pictures.

 

[oldman570]

Re: Impeller Pin/Key

The 9.8 Mercury motors did have two different impeller keys and the impeller brass centers are of different inside diameters. One had the flat spot on the drive shaft that used a flat backed key with the knobbed rounded front side. The other use the pin type where a small pin was placed In the shaft and the impeller has a notch in the brass center. If you use a Sharpie magic marker and slide the impeller over it you will see that one impeller will slide clear up on the sharpie and the other type will not go up onto the flat part of it. The best way to get replacement parts for the motor is to go to a local Merc dealer with the old impeller and he will be able to get the parts needed or should know the motors that use them. JMO
Oldman570

 

[carholme]

Re: Impeller Pin/Key

Mercury Outboard Parts | Mercruiser Parts Catalog

See item 35, p/n 17 39076

It is available at a competitors site which this site will not allow us to post. See my message to you in Notifications at the top of this page and I will give you my email address.

Gerry