Do impeller fins go opposite direction on counter rotation outboard? (150 CXL)

[Luke415]

I made the mistake of taking the impeller off of the shaft before checking to see which way the fins were pointed while rebuilding the water pump on the 1998 150 CXL engine I have. Does anyone know if the impeller rotates in the opposite direction on a counter rotation merc?

 

[Chris1956]

The impeller will orient itself to the correct direction, so that is not an issue. I think Merc CR outdrives run in forward using the rearmost gear, and a heavier bearing and bearing carrier. On a conventional gearcase the rearmost gear is used for reverse.

 

[Dukedog]

kinda what chris said... all "production" merc/mariner V6's turn clockwise... Counter rotation is done in tha gears, doesn't effect tha pump....

 

[Luke415]

The impeller will orient itself to the correct direction, so that is not an issue. I think Merc CR outdrives run in forward using the rearmost gear, and a heavier bearing and bearing carrier. On a conventional gearcase the rearmost gear is used for reverse.

Thanks for the info. However, I have heard that when putting a new impeller in the water pump housing, you need to orient the fins in the direction that they will naturally spin to work correctly. For example, I took my old impeller out and one of the fins was twisted and pointing the wrong way, leading me to believe that could be the reason I was not getting enough pressure through the tell tale... Is this not true? Thanks!

 

[Luke415]

kinda what chris said... all "production" merc/mariner V6's turn clockwise... Counter rotation is done in tha gears, doesn't effect tha pump....

Thanks Duke

 

[Dukedog]

if new and doesn't "orient" itself (V6 anyway) needs ta go in tha trash and try another........thats tha reason tha pump housing is actually offset a little in relation to tha drive shaft...

 

[racerone]

????----The pump housing is offset so that the volume between the vanes changes.----That is what provides the pumping action at lower speeds

 

[Dukedog]

volume and pressure..... but also gives it room and angles ta orient tha blades....thats tha reason tha pump housing is actually offset a little in relation to tha drive shaft...

"thats ONE reason tha pump housing is actually offset a little in relation to tha drive shaft"...

is that better!.

 

[Luke415]

Thanks. Anyone know the torque specs for the bolts that hold the thermostat? 20lb? 30lb?

 

[Luke415]

Thanks. Anyone know the torque specs for the bolts that hold the thermostat? 20lb? 30lb?

Nevermind, think I found it. Seloc manual says 200 inch lbs, or 16.6 foot lbs