How often do you change your water pump impeller?

[NiceAft]

Matt,

I was always told two years, and then replace the impeller. Unfortunately I totally forgot the rule, and never replaced it. In 2008, while still in Lake George, upon starting the motor to leave the slip one day, I notice the that there was not any pee stream shooting from the engine. I could not find a cause, but I had suspicions In my case, I made use of my towing insurance with BOATUS and towed the boat to the ramp (only one day early) and put her on the trailer. When I got her home, Eckert Marine (near you) said it was the impeller. they took care of it. They are very fair, and very good to work with.

From now on it's every two years. I got away with very little expense, while others did not.


Ray

[c130king]

Do the general ROT's (rules of thumb) on replacing the impeller apply equally to 2-strokes and 4-strokes? I have never replaced mine...I doubt the PO ever did which puts my impeller at 5+ years old (however, the boat has sat unused for over 2+ years while in storage). The engine probably has 300-400 hours (a guess). But it "pee's" very strongly. It has been used in fresh, brackish and salt waters.

I will be looking into this when I get back to the boat this Summer.

Cheers,
Jim

[opie]

Jim,
After your next pint of Guinness, and if your Mac is on the hard in the States, call and have a friend spray some penetrant (not WD40 lubricant) on all the bolts for the lower unit. It may be ready to loosen the bolts by the time you get back to the USA.

[c130king]

Jim,
After your next pint of Guinness, and if your Mac is on the hard in the States, call and have a friend spray some penetrant (not WD40 lubricant) on all the bolts for the lower unit. It may be ready to loosen the bolts by the time you get back to the USA.

Don't tell me that.

I will deal with it in 6 or 7 months...

Cheers,
Jim

P.S. It is snowing like crazy here in my part of London right now...over 3" at my house...didn't go to work today. Sure wish I was back in Florida.

[Kelly Hanson East]

Jim - The Mercury recommendation is 3 years or 300 operating hours.

Confession time - my 2003 Mercury 50HP impeller is original....I estimate I have about 1000 hours on the engine. My rationale for this abusive practices is threefold...

1 My cruise rpm is 2000-2500, I have run the engine at WOT about 5x in its life.
2 I have a like new water stream
3 I predominantly use it in fresh water, and rinse after salt
4 I carry a spare impeller and tools at all times
5 I have a backup motor

You can test your water pressure (warm engine) by putting a barbed fitting on the engine and checking against specs

RPM psi
1000 5.5
2000 8.5
3000 12
4000 14.5
5000 17
6000 20.5

Assuming you are doing this on land, I wouldnt exceed 3000 rpm for this test (per Mercury recommendation)

[c130king]

Stephen,

Thanks for those numbers. Don't have a guage but it pee's nice and hard. I do run at WOT a good bit. I do rinse the engine out good when I pull the boat out of the water...and even did it a few times in the slip when slipped for 8+ weeks.

But it is obviously time to replace. I have to research the engine warning horn issue anyway so I will be doing some engine work when I get back. I am not a "motor head" by any stretch of the imagination but I am looking forward to digging into my engine for both of these issues.

Do you know how I get a manual that shows 1) engine warning horn replacement/repair and 2) impeller replacement for a 40-HP 2-Stroke?

Thanks,
Jim

[sctodd]

found this link to show how to change out your impeller
http://www.idofishing.com/forum/showfla ... eplacement
I haven't changed mine yet it is the original in a 2002 honda 50. will change it this spring before launch

[Russ]

found this link to show how to change out your impeller
http://www.idofishing.com/forum/showfla ... eplacement
I haven't changed mine yet it is the original in a 2002 honda 50. will change it this spring before launch

Yikes!

That looks so complicated. I wonder if it's the same process with the Suzi?
So this isn't something that can be done in the water. My old Yanmar had the impeller right in front of the engine. So easy to replace.

--Russ

[Kelly Hanson East]

I think you could do the swap in the water, standing in shallows, but I would sure want some back up hardware - especially those mounting bolts, for the inevitable ker-plunk...

[The Mutt]

An engineer mate of mine says to change the Impeller every 1 to 2 years, he dodged my question for a while about when he last changed his impeller "a bit over 5 years, I might do mine this weekend" was the final reply, that was in September, he still hasn't done it.

I did mine the middle of last year, currently changing over the fuel diaphram and the carb needle, might idle properly then.

Glenn