Life time of a Raw water/livewell pump

I have a Flowtek (I believe thats the name) raw water/livewell pump that puts out 4-4 1/2 gallons per minute. The pump is 4 years old. What is the general life expectancy of these pumps?

When I run my livewell the pump will shut off and my fuse pops. Same goes when I run my raw water, after washing down the deck it will shut off and the fuse pops. I took it apart and cleaned the screen, blew out the tubes to the pump and re-wired the connections.

I haven't tested it in saltwater yet but do you think its time for a new pump?

Thanks!