Yamaha Transom Plate mod
This service has our machine shop bore the 155mm transom plate to match the 160mm wear ring. This is not a straight bore! It is a beveled angle all the way through, so there is no lip at the hull mating surface. This is a more difficult but better way to bore the transom.
Removing the 5mm "step" between the transom plate and wear ring will greatly improve performance and help limit cavitation.
The first picture shows side by side of before and after the modification, notice the large lip/step in the before picture.
The last two pictures are an un modified transom plate.
Turn around time is only a few days!