Originally Posted by Dan Gurney
Interesting stuff. Think I'm going to let the engine bed in a bit (still only just over 20 hours on) before messing with the prop. We had 37knots on the GPS with 150 litres on board in Ireland but I don't think RBs are set up for speed: mine has a noticeable offset and is set quite low resulting in a bit of splashing round the transom.
As has been said before if I'd been concerned about top speed I probably wouldn't have bought a Redbay. Not ruling out playing with props later on though.
Dan, I'm in a similar situation to yourself, i.e. shaking down a new boat with a DF140. I have lifted my engine 2 holes from where it was set by Ribcraft. I had a lot of splashing around the transom, landing heavily on the port side after being airborne
porpoising at high trim etc. Also the prop would cavitate badly to the point that the rev limiter kicked in, this was when landing after "catching air".
We took the boat to Whitby on Sunday after raising the engine & putting 25kg of sand in the bow. The weather was interesting
, we headed north into a 2m head sea & the difference in handling was marked. The port list has gone, she lands straight & with no cavitation on landing, the prop bites straight away (I can't explain why lifting the engine would reduce cavitation, but that's props for you). It was too rough to try WOT, but I got her upto 5500.
I have the 21" ally prop on at the mo, which I think is about right. I got a SS as part of the deal, but we are waiting to decide which one to go for until we determine the ideal pitch.
Personally I prefer to run slightly underpropped as it gives better response in the rough for the sake of a few Kn at the top end. I'm a big fan of 4 blade props for the increased grip that you get, but I've not looked into them yet to fit the Suzuki. Unfortunately the Mercury Rev4 doesn't fit