Selva Tuning: Installing Hill Marine Semi Cleaver propeller (Part 1)

I'm looking for more top end speed and think I have hit the performance barrier as far as Solas aluminium propellers are considered. Hill Marine has a nice selection of stainless steel propellers so I decided to get one for my Selva Madeira 40 XS from Ebay. Unfortunately they do not advertise propellers for 2T Selva outboards so I decided to buy a propeller labeled as "Signature-Semi-Cleaver-13-Spline-Race-Propeller-18P-for-Yamaha-F18R3L-117". After all I have been using Yamaha G-series propellers without problems so this should fit like a glove!

Hill Marine Semi Cleaver 11 1/4 X 18

This propeller came with a Michigan Wheels XHS hub kit 117 for Yamaha.

I tried to install this hub kit and quite quickly noticed that although Selva Madeira 40 XS is compatible with Yamaha G-series propellers it DOES NOT mean that one can replace the stock thrust washer with Yamaha thrust washer that comes with XHS hub kit 117!

Both have 13 splines which is fine, the problem is that Selva thrust washer has narrowing teeth whereas Yamaha thrust washer's teeth do not narrow. Hopefully the images below give some explanation.

Selva Madeira 40 XS stock thrust washer

Michigan Wheels XHS 117 thrust washer (part number 991243)

It was possible to install the propeller but due to differences in the shape of teeth the propeller was a little "shaky" and I'm not comfortable to use it like this. I'm not sure how to proceed, I might alter the XHS thrust washer or find some way to use stock thrust washer with this Hill Marine propeller.

I'll post an update once I have figured out what to do. If you have some information please use the commenting functionality below! :)