When you replace your impeller use a quality Mercury part, I bought a Sierra pump kit and kept it on the boat just in case. I put it on a year ago yesterday. Never had real good water pressure with it (10 psi max). Well yesterday I was coming back to the marina and came off plane and our gas dock girl said there was alot of steam coming out of my exhaust. Thought maybe it was the cooler air and water. Gassed up and went back out, now I'm nervous and am stareing at the water pressure gauge.....and sure enough within 20 minutes the pressure dropped from 8 to 7 to 6 to 5psi. So i nixed the run down the bay and went to our favorite spot to look things over and still be on the water. (and get rid of my hangover) We took the pump out and apart and 2 of the fins were broken off and luckily still in the housing, all the other fins were cracked and ready to fall off. Get this, saturday before we left the marina for the weekend I bought a Mercury Quicksilver impeller (just an impeller) and put it in the tool box, something told me just to do it. We put the impeller back together and alls well....15 psi and no steam

So....to make a long story longer, buy quality parts. The Sierra part lasted a year to the day. The previous impeller was in for 3-4 years (a Mercury part). Yea Yea I know you should change your impeller every year. Spend the extra few dollars you get what you pay for.

my merc one only lasted 8 hours

Merc all the way...the sierra ones are crap and the blue "run dry" ones usually slip too much equalling low water pressure

This weekend I had an impeller go bad on me---the water temp gauge needle was wandering from 140* to 195*. We found one of the fins broke off the impeller and the others looked cracked at the base.

Did it look like this.....

I'll second that... We installed a Sierra impeller on a friend's boat and could not get it to pump at all. Even primed the pump with the garden hose. After scoring the inside of the housing, we replaced with a Merc pump.... Full flow & pressure.

Yes, exactly like that, but the cracks at the base of your impeller that you have in the photo looks more advanced.

Sierra part.....exactly one year old

Anyone want to bet that the Merc part is actually a Jabsco piece with the price doubled (or more...)??
I run Jabsco pumps bolted directly to nose of the crank, so they're super-easy to work on. I average 3 years on impellers, but I usually loose them to blocked water flow (and therefore over-heating), not old age.

Remember Chuck.....I ain't got one of them fancyass sea strainers either.