Not to sure what the weather has been like in the rest of the country, but its not been the best boating conditions in the South West over the past few days, rain and strong S-SW winds. However late this afternoon, just before high tide, the sun came out, the wind dropped and it was relatively calm.
It was just the kind of conditions to do the prop tests I had wanted to do since fitting the new keel board -
https://www.rib.net/forum/f50/airdec...ign-87561.html.
I've not been happy with the sound of the OB since fitting the new keel board, it sounded somehow higher pitched. Top speed was good and handling was great, but something in the back of my mind just wasn't right, but I couldn't test it at the time as I didn't have a tiny tach fitted.
2 up + dog, usual load and with the prop I had on the OB before I'd fitted the new keel board, 9.25x8 (
https://www.rib.net/forum/f50/prop-pitch-84693.html) RPM @ WOT is 6390/6450 rpm and top speed is 17 knots. Good top speed but well outside the RPM operating range, very different from before I'd fitted the new keel board.
Changed the prop to the OE prop that the OB came fitted with, 9.25x9. Same load, RPM @ WOT 5950/5975 and top speed 18 knots, really happy with the top speed and RPM is within range but noticeably the pitch of the OB has dropped, it now sounds like it should.