.....what factors should i use in determining when to replace my wear ring...i inspected it today, there are scratches no "groves" but the paint is gone all the way around the wear ring and with the stator out the shaft moves ever so slightly.... i get paranoid about my lake time and i do not want any thing to get in the way of that. SO i guess what i am asking is what are the affects of leaving it the way it is and how hearty are these parts.....when do i know with out a doubt that it is time so spend the $.....is reg valv hi performance gear lube ok to use in the stator? Thanks for your time!!!

Jetwild for PREZ

Straight from the Mercury service manual:

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1. Place impeller in wear ring bore and push to one side.
2. Measure clearance between impeller blades and wear ring with a feeler gauge. If clearance is over 0.100 in. (2.54 mm), replace impeller and wear ring.

NOTE: Impeller wear usually accounts for 75% of the wear. Reducing the clearance can improve both top speed and acceleration performance.

COMPONENT SPECIFICATIONS
Wear Ring Bore Diameter 7.273 - 7.283 in. (184.73 - 184.98 mm)
Impeller Outside Diameter 7.225 - 7.235 in. (183.52 - 183.77 mm)
Clearance between Impeller and Wear Ring 0.038 - 0.058 in. (0.96 - 1.47 mm)
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My wear ring looks like your description. With the stator installed and measuring with feeler gauges, I have ~0.015 inches of clearance all around. That's 0.030 cumulative inches based on their "shove it to one side" procedure above, well within specs and actually below the low range of their clearance spec (last item above).

Get a set of feeler gauges and see what you really have.

thanks for the advice i will check it out when i get get the gauges. One more thing the valv. HI performance gear lube is sufficient or is there something else i should use in the stator....

If your question about Valvoline is driven by price, consider that you need only two bottles of Mercury's product to change the front AND rear lubes. Doing it once per year (as recommended) doesn't add up to a whole lot of money. I'd stick with the proper lubricants. That's a $10,000 engine you're gambling with.