When to change water impeller?

[kungpaoshizi]

So my g/f started the motor while it was partially out of the water, 77 mercury 1150..

It's still pushing water out of the pee hole, but it got me thinking, other than opening the lower unit and taking all that out to look, is there any other way to detect when you need to change the impeller?

 

[gm280]

Re: When to change water impeller?

Seems most usually change their every two years. But I don't know of any set time intervals myself. I lean towards sooner then later myself because it is so easy and it really doesn't cost too much. So I figure a little time and few dollars are much better then a toasted engine rebuild... But that is just my opinion...

 

[sutor623]

Re: When to change water impeller?

WHen was it last changed? How long did you run the motor while out of the water? Had it been submerged during the day, or was it completely dry?

 

[RogersJetboat454]

Re: When to change water impeller?

Impellers should be routinely changed while they're still fully functioning.

Looking for a drop-off in their performance is like waiting for the oil pressure light in your car to flicker before you feel the need to do an oil change. It's the vital life support of the engine that needs to be MAINTAINED, rather than running it till it starts to fail.

In other words...
If you don't know when it's been changed last, it's time.
After that, make it a point to change it every couple or 3 years.

 

[kungpaoshizi]

Re: When to change water impeller?

It was in the middle of the day out on the lake, it was running shortly before that so not at all completely dry, and it probably ran only 15-30 seconds before we noticed... I really wish there was a temp gauge...

It seems to be running fine and water still comes out the p-hole, but I recall seeing in the manual a warning of "even 5 seconds running with no water will RUIN the water pump!!"

 

[Chris1956]

Re: When to change water impeller?

Kunk, That motor doesn't have a thermostat. The impeller is sized to pump a bit more water than the engine needs to keep cool, at a given load and RPM. If the impeller is not working well, you will fry that baby.....

You will find the motor runs dead cold at idle, and warmer at cruise, warmer still at high speed.

 

[55evinrude]

Re: When to change water impeller?

just change it....... as a merc tech i can tell you that its not worth the risk of leaving it, by the time you realize its not pumping anymore it will be to late. sure Ive seen impellers run for 1-2 mins dry and didn't look all that bad when removed but Ive also seen ones go in 10-15 seconds and be completely destroyed it all depends on the age of the impeller, either way just do it!

Nathan

 

[Mi duckdown]

Re: When to change water impeller?

What 55evinrude posted. peace of mind.