Jabsco 4900 200 impeller change

[Cattleya]

Can someone please tell me if I need to remove the woodruff key to change the impeller on the Jabsco 4900 200 pump, or can I just pull the old impeller off and replace it without touching the key? 

Rather strangely whoever changed it last time (not me) put the cover on at weird angle!

[Tony Brooks]

13 minutes ago, Cattleya said:

Can someone please tell me if I need to remove the woodruff key to change the impeller on the Jabsco 4900 200 pump, or can I just pull the old impeller off and replace it without touching the key? 

Rather strangely whoever changed it last time (not me) put the cover on at weird angle!

 

I might be able to answer that. If you have a fair bit of shaft sticking out in front f the pulley, then you can probably just slide the impeller off the shaft. This is because the impeller has been reversed in the pump, pushing the shaft forwards.  As fitted as standard on the 1.5 (that is what yours looks like) the pulley prevents you moving the shaft far enough backwards to pull the key out so you can easily remove the impeller.

 

On the fleet, we found that the need to take the pulley off each time a customer ruined an impeller soon led to the pulley becoming loose on the shaft, so we found that it was easier to move the shaft forward and reverse the impeller. However, be aware that if you do that, the shaft will only run in about half the bearing in the back cover. this caused us no problems and made "up river" overheating problems far easier to resolve.

Edited February 4 by Tony Brooks

[Tracy D'arth]

I never take the woodfuff key out. Just pull the old one after noting which way the vanes point.  Don't forget the grease.

[Cattleya]

Thanks Tony and Tracy. 

[Tony Brooks]

I suppose Jabsco might have seen the design flaw and altered the position of the key, since I dealt with them