23 w/225 four stroke - Prop issue

[schooner]

Just repowered my 23 sceptre with a Johnson / Suzuki 225. Mechanic installed a 4 blade 14.5x17. with a 2.3 reduction, this is way underpropped. Numbers are 9 mph @3000 - 15mph @3500 - 19.5 mph @ 4000 - 28 mph @5000 - 31 mph @ 6000

My target was 28 mph @ 4000. Can anyone who is running a 225 four stroke on a 23 share their prop size and speed numbers so that I can see if I'm on target. Trying a 16x17 this weekend. Not sure what to expect.

Thanks