Sanity check, tightness of new impeller

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Working on my '87 90hp rebuild. With no gear oil installed, and no impeller, the shaft turns nice and easy by hand. LU is off and on bench.

Once i put in the impeller and housing, it will turn but its very difficult. Lower is off the housing too, on a bench. Yea, blades are curved in correct direction.

Ive done alot of these and cant remember it bieng such a drag on movement. I put some vasoline in the housing on install.

Its tight enough, i feel it will be a drag trying to start the motor. I have 110lb compression on the loose powerhead. I bet once together, it wont spin up to speed to give me those readings again

Thoughts?
 
Last edited:

rothfm

Ensign
Joined
Sep 26, 2006
Messages
915
Thank you sir. That rubber sure was stiff going into housing. Just seemed tight. Probably will feel different as it takes its shape over time

Thanks
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Just remember those impellors are a displacement type pump at low speeds and therefore have to be tight to work properly until high speeds. Then it becomes a centrifugal type pump. Sounds normal to me.
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
Like to check for that drag when getting ready to bolt up the l.u. -- feel the impeller turning when the shaft is turned.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
That's the same impeller/housing used on all the crossflow V6 engines, so it's a heavy duty one.
 
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