Impeller change interval

[knotflying]

I have a 2021 Yamah 300 HP 2021 with about 125 hours. The manual says to change the impeller at 300 hours. I am looking for input from others to see if doing it sooner is advisable.

 

[captmatt]

On my 4.2 L F250 I change my full water pump (impeller, plate, plastic housing, etc.) every three years at what is usually around 250 hours. That is a bit overkill and I could change the pump at four year intervals given my use. But that way the bolts are not going to be seized and everything comes apart without much trouble. The impeller always looks fine although by three years there is a permanent curve in the veins and it is less flexible.

I suggest you dab a bit of marine safe anti-seize on the bolts when you change the water pump.

 

[tomc585]

unless you've run it dry or you have a weak flow you can go much longer. I know it's an easy job but doing a water pump impeller every year is not necessary...same for spark plugs.

 

[A-K]

Assuming you store your boat through the winter. I would change it in 1 year before the beginning of the 2024 boating/fishing season.

 

[Mpellet]

I was on a 3 year cycle when I had a Yamaha F225 on my boat. That translated to approximately 600 hours with almost 0 skinny water running. The impeller always came out looking almost like new and I never had a problem getting the lower unit to drop for the 1800+ hours I ran the Yamaha. I repowered with a 2019 Suzuki DF300APX. The Suzuki 6 cylinder four stroke outboards have a bit of a reputation for stuck lower units and the annual maintenance kit that I buy comes with an impeller, subsequently I have replaced the impeller annually. I do not think that’s necessary for impeller wear but with the Suzuki’s, annual removal, lubrication and replacement of the lower unit is IMO a very good idea, subsequently the impeller gets replaced while I have the lower unit off.

I haven’t read any issues with stuck lowers on the Yamaha F300, if it were me, I’d be comfortable with a 3 year duty cycle on the impeller….

 

[warthog5]

150hr change for inshore.......200hr for change for Offshore.... and NOT just a impeller..... The Complete Waterpump Kit..... Also OEM parts.


I've used aftermarket parts before.....They don't last near as long.

Another Major reason for dropping the foot.....Greasing the Driveshaft spline.

This prevents the lower unit from becoming stuck....[Read Welded to] the Crankshaft.

 

[tomc585]

Funny you should say that....
I was poking around the boat yesterday and decided to drop the lower unit on my yami to have a look see.....so much for being told it was a "new" unit.
I was not a happy camper.
On the plus side I was able to get it apart without too much savvy. It will be like new when I'm done.