Johnson 150 - how many hours per water pump??

[Jmh9000]

I've had this 2001 Johnson 150 (carbed) for almost two years (third season) now. I've put about 150 hours on it since I bought the boat and I'm about ready to replace my FOURTH water pump. My slip is a bit shallow at low tide and I do stir up some silt . Can this silt destroy an impeller so quickly? I'm only seeing 30-40 hours between impeller replacements.

I hit the overheat cut off buzzer early on and have installed a Cyl head temp gauge and water pressure gauge so I never hit that alarm again. Now I'm again seeing head temps running warmer than normal (180 vs 145-150) and water PSI running lower than normal (low 20's at WOT rather than high 20's)

I'm now ordering my 4th water pump in less than two years. The last three have been Sierra so I'm thinking of changing to OMC and see if i get better life. Are there any other brands that people have had luck with?

For the record, I'm a pro at dropping the lower unit. I have the whole job down to about 1.5 hours.

 

[dingbat]

You shouldn't be going thru impellers pumps that quick.

I change my impeller based upon water pressure and average 2-3 years (200-300 hrs.) between impellers. Change out the pump housing every other impeller.

Kicking up a bunch of silt, how often do you flush?

When was the last time you had the stats out for inspection?

 

[oldboat1]

I had a shallow slip in a brackish creek, and poled out into deeper water when the tide was low. I got by with annual impeller replacement, but did have an overheat incident when I let it go too long. So I can see where running in salt and silt might mean a couple of impellers each year, depending on how you run. If trailering, I would definitely flush after every trip.

 

[Jmh9000]

Puled the thermostats out in May when I did the impeller. Everything was fine.

it's a freshwater boat and in a slip so I don't flush regularly. if I do stir up the silt I make sure the water is running clear from the tell tail before I shut down (lazy man flush)

 

[Scott Danforth]

silt is abrasive..... so yes, that will wear out your impeller and housing.

 

[dingbat]

I went through a similar issue a while back.

Turned out I had the wrong pump for my motor. Would have never know unless I had a pump installed by the dealer while in for routine service.

WOT pressure was up 10 pst, Idle up almost 5. No idea why they make 2 different kits

Personally, I would get an OEM kit from the dealer to make sure you have the right kit for the motor.

 

[thatone123]

Believe it or not I know of some 20 year old impellers still going...but do not recommend it. I run in shallow muddy water all the time and few water pump problems except weeds sometimes have plugged the water pump when they have got in there. I think of average a impeller will last 5 years and the pumps longer.

 

[flyingscott]

Most manufacturer recomend 3 years on a pump. but there are exceptions for certain water conditions. Pulling it out of the water allows the silt to dry out in the impeller housing. When you start it you basically start the pump on sand paper.