Do it yourself...its an easy job. Every couple of years replace. I recommend buying the kit to start with. Do not by just the impeller. I like the kit if I do not know all the history of the engine...that way all the gaskets and housing are new. That price is high also. Its a very easy job. Have some dish washing soap with you (liquid) will make installation much easier.
"But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.” Joshua 25:15
Lube the impeller to install with the dishwashing soap.
This would be a great sticky for someone to post photos of this changeout and post it. We could all learn.
It's not the numbers or the size, it's the time spent on the water!
YouTube - HOW TO REPLACE WATER PUMP "MERCURY 150 OUTBOARD"
Video 150 merc. water pump change
When I reassemble I cover it all with dishwashing soap. Makes it much easier to reassemble...plus you do not have a dry start...with new impeller. I know you'll have muffs on it...but I like knowing its slick in there. Also when you get it done...turn the shaft...if working properly you'll see bubbles push out of the pickup tube. Main thing is its SOO much easier to put back together. Once you get the impeller on the key cover with the soap and as you push the housing down...turn the shaft in the rotation of the engine and she slides right on. Always be sure to look at the direction of your blades before you throw the old one to the side so you know how to turn the shaft before you put housing on the impeller. That way the blades don't get bent and possibly tore when it turns the correct way.
"But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.” Joshua 25:15
Keep in mind that an impellor change and a full water pump kit are 2 different things. For instance a Yamaha kit probably has about 6 or 8 different parts, impellor, baseplate, housing, seals, o rings and a woodruff key. That can be the difference between a $75.00 job and a $150.00. I think my Yamaha kit was $75.00 itself.
Thats why i'd do it myself...kit is just better to start with. IMHO. You can get a sierra or mallory part cheaper than a merc/johnnyrude/yammie etc. Water pumps are great from aftermarket suppliers. Mech parts I like OE....and electronics I like CDI....just what I like to use. I try to stay away from sierra and mallory for electronics and mech parts.
"But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your ancestors served beyond the Euphrates, or the gods of the Amorites, in whose land you are living. But as for me and my household, we will serve the Lord.” Joshua 25:15