Impeller/water pump question?

[Carson]

I have a Mercury 175 that has plenty of water pressure and cools the motor fine it just doesn't have the stream of water you would expect at idle. I can not find anything blocking the system or anything like that. Some have told me that its something I am going to have to live with. I was curious if anyone knew of a high flow impeller or water pump that I copuld put on it. Does one even exsist? Is it worth the trouble?

[jhworley]

I have a Merc 90/65 Jet. I noticed, after 3 years, that the stream coming from the "pee hole" was very weak, and almost just dripping. I noticed it at idle, but when running it was shooting water out.

I called Merc and they just said it was due to the water pump IMPELLER getting weak. I read the service manual, bought the $35.00 part, and 2 hours later was done. Tested her out and she was ticking like a champ.

Now, I don't know if you are experiencing the same issue as you have a bigger motor and a different lower unit... however you still have a water cooled power head.

My guess would be your impeller is weakening and just needs replacing.

jhw

[Jig Man]

I have a Mercury 175 that has plenty of water pressure and cools the motor fine it just doesn't have the stream of water you would expect at idle. I can not find anything blocking the system or anything like that. Some have told me that its something I am going to have to live with. I was curious if anyone knew of a high flow impeller or water pump that I copuld put on it. Does one even exsist? Is it worth the trouble?

What is the pressure at idle?

What is it at wot?

[fishfordollars]

My 150 Merc does the same thing. Once your on the throttle it is fine and I have quit worrying about it. We change it out about every 18 months and it has always done this.

[Carson]

At idle it jumps around between 5-10 and wide upon the pressure is around 20. The way it jumps around makes me question the auge a little.