impellor protruding from wear ring

[callan FNQ]

hi gents,

how much of an adverse affect does having an impellor overhanging the wear ring affect performance ?
I made new cutlass sleeves for my 770 3 stage on the weekend,and thought rather then just make identical length sleeves i would measure clearances to ensure the impellors are correctly positioned and are not too close to clipping a stator.
edge of the centre and rear impellor was positioned flush with the start of the wear ring, though the rear tip overhangs slightly on both centre (about 2mm) and rear (about 6mm) impellor.
front impellor is a 4 blade stainless bullet,

i havent bothered to measure impellor angles, as for performance,14ft glass heavy as hell no name hull, fresh 351, 93mm nozzle, 84km/h on calm water at 4k max revs. minimum plane is around 30km/h @ 2500.
do you think they are pitched too aggresively ?
to me holeshot is good, no slip or struggle and on the plane in a length or two of the boat
though the jet is quite noisy while heading upstream, fair bit quieter heading down.

any suggestions ?

thanks.

[mohawk]

Sounds like it goes pretty good. Motor should last for ever at that rpm .

[Paul]

Isn't that blade in backwards?

If you look directly below the nut where the blade meets the wear ring, it appears to be a progressive-pitch blade, with a decreasing pitch...  Or maybe that's just perspective in the photo.

[mohawk]

Isn't that blade in backwards?

If you look directly below the nut where the blade meets the wear ring, it appears to be a progressive-pitch blade, with a decreasing pitch...  Or maybe that's just perspective in the photo.

you may have a point there paul 

[Paul]

Heh Callan, did you manage to sort this?  What were the clearances when the blade (/blades??) was/were turned around?