ratio

Does anyone know the reduction ratio for M-40/5432 engine /w Hurth HBW-100 transmission. I ordered a new three bladed prop awhile back, and I think I'm slightly overpitched as I can't get tach beyond 2150-2200 rpm. Below is an exchange I had with the prop folks. I guess most succinctly, is the...

Just wondering if anyone knows if we have an HBW100 or HBW150 transmission and what the ratio is. My boat is a 1986 38-200 with an M40 based on a kubota V1502 block. I can't see the tag properly with the engine installed....maybe with a small mirror if no one knows. thanks shaun

We are interested in changing the prop on our 39B to a 3 blade feathering design. We have pretty much decided on the Kiwi Prop. They would like to know the transmission gear ratio, and I have no idea what it is. We have the original Perkins 4-108 combined with a Borg Warner transmission. I...