Re: Mercury motor impeller and idling
The rule of thumb is replace the impeller every 2 years whether you think it needs it or not. Better to be safe than sorry. As long as there is water going through the pump,it should be able to idle for a very, very long time. You should have an overheat alarm on your motor. Also, you can install a pressure gauge.
I've been thinking about going with a 135 Optimax. Tell me how you like it.