Impeller Question

[okiepilgrim]

When it comes to replacing an impeller on a water pump, I have heard 2 opinions. One is that you should rotate your impeller during installation in the same direction as the pump rotation to get the splines in the correct "direction". The other is simply that it doesn't matter and will get in the correct position as soon as the impeller turns. Looking at the picture I took, I find it hard to believe you could get the splines to be "backwards" after first run, but I'm an idiot and want y'alls thoughts.
I'll also concede that it may vary by pump. This is a Johnson.

IMG_5378.jpg

[chpthril]

Id want to get them turn the correct direction during installation. Not a lot of room flip them after the fact.

[lee]

Use some liquid dish soap and water to lube during the install will help also.

[BCRider]

I twist mine as I install it but not usually worried which way the splines go. Once you start the boat or even turn it over they will get repositioned to the correct way.

[scottspray]

Had an impeller come apart right after installing once.
Not sure if I had it going the right direction.
I’ve made sure to install them with pump rotation ever since.

[freeheel4life]

https://youtu.be/-B2tgs2pDNY

Lubed with dawn. The vanes will flip over. I wouldn't test that theory on some outboard impellers. Less vanes but they are all way thicker.

[okiepilgrim]

I was thinking after reading some earlier posts here that I was going to basically do this same test next change. But now I don't have to! Thanks freeheel, this was my guess just looking at mine where the vanes are basically straight out on the opposite side of the "bump".

Obviously doesn't hurt to rotate the right direction, but it's such an awkward angle and PITA to get in, I'm certain I won't always get it right.