Changing Impeller on a Mercury 4hp 4-Stroke...?

Question

Due to the lack of the tell-tale 'squirt' of water from my outboard, I'm about to change the cooling water impeller on my 2006 4hp Mercury 4-Stroke Sailpower.

Where is it? It is the first time I've needed to change it - can anyone direct me to a diagram as to the position of the impeller or describe where/how to remove it?

Many thanks

Answer 1

The impellar is in the bottom gearcase. You really should buy a repair manual for this motor if you plan on working on it yourself. A repair manual costs about $25-$30 and will pay for itself many times over. You can buy one at a mercury dealer or www.selocmarine.com or several other places on the web.

Answer 2

Hi Adam!

Before you do the surgery to replace the impeller, the check-hole of your motor may simply be plugged. I've had to use a toothpick to clear debris from our Honda15 many times. I change the impeller on our motor every three years and keep the old one as a spare. Unless you've run the motor without water... they're almost bulletproof.

It's not really rocket science to change one out. AFTER removing the prop...

1) Mark the position of the gearshift linkage with a Sharpie, then unattach it.

2) Remove the bolts attaching the lower leg to the main body and remove it.

3) Slide the impeller off the spline.

Clean old gasket off housing, use new gasket, reassemble in reverse order. Make SURE to attach and adjust gearshift linkage EXACTLY where you marked it!

Good Luck!