I have a 1979 9.8 mercury outboard. The old impeller needed to be replaced. I've ordered 2 from Marine Engines now and neither would easily go on with the key. Specs I found on-line state that there is a minor diameter change in the shaft on some model year( don't recall exactly now) but I've been very careful about ordering for my serial number motor each time. When I say it won't easily go on, I mean if you can ever get it started over the key, you can then use a box wrench over the impeller center and with a ball peen hammer you can convince it to go on... pretty certain this ain't right. The old one can be slipped back on over the key with minimal pressure, but then it's worn in.
Here's what I'm wondering.. I'm not the original owner. I thinking it is possible someone replaced the foot on this with an older one some time in history which would account for the minor shaft diameter change. I can see some numbers stamped inside the lower unit, but I don't know how to decode them. Could these possibly indicate year of manufacturer of the lower unit?
It's that, or they are repeatedly shipping the wrong impeller. The other option is this requires pounding force to install by design, but that would really surprise me.
Here's what I'm wondering.. I'm not the original owner. I thinking it is possible someone replaced the foot on this with an older one some time in history which would account for the minor shaft diameter change. I can see some numbers stamped inside the lower unit, but I don't know how to decode them. Could these possibly indicate year of manufacturer of the lower unit?
It's that, or they are repeatedly shipping the wrong impeller. The other option is this requires pounding force to install by design, but that would really surprise me.