So, I just purchased a F34 DCB with 1.24 #6 drives and 4 blade 32px16.25". From what I have read these boats go through quite the mid range instability when transitioning to air out, I would like to minimize this with props. I am thinking 15* five blades to try to carry the stern in the transition. So, adding a blade should I go down an inch in pitch? What diameter? Would a 6 blade be any more beneficial?

Thanks,
Jeb

Congrats on the new ride. I assume you mean it hops until aired out. Does it have a tunnel tab?

Yes, I know that it is a trait of air entrapment hulls, some are worse than others. F34 was known for it and you need to drive through it. I know some Skaters are also subject to it also.

There is one guy that made his a walk through open bow and it does not hop at all. It added weight to the front, I have thought about moving the batteries or doing testing with sand bags. But why not use props for the lift and keep the weight where its at? although 10k for #6 props...might be easier to move the batteries.

There are lots of speedmaster owners that will allow you to borrow a set for testing to find a combination that works. I have lots of smaller props that I can no longer use due to gear changes and different boats. Nice Dcb. Doug

Thanks Doug, would you have any 5 blades or 6 blades in the 30 to 31 pitch range? Low rake preferred.

Do not know of many cat owners running 6 blades. I have a perfect set of Herring 5 blades 31X17 18 degree that I can't use. These are in new condition. $5200 in cases shipped to your door. I have a set of Mercury Racing 29X 16 5 blade checked and serviced by BBlades. $4000 shipped to your door in cases. Bunch of Mercury 4 Blades in 30 to 31 pitches in the $2500 range. My props are represented correctly. I have been burned and know what a perfect prop is.

What 4 blades are you running at what rpm? I have 3 sets of props that I use. I use a set of 35X17 Herring, 36X16.5 Mercury Racing and. 37x16.5 Mercury. I usually run the Herrings but the 36 Mercurys are closer to 37s and the 37s are closer to 38s so I run the bigger wheels on long smooth runs when I know the cruise speeds will be around or over 100mph for long periods. Doug

Sorry about the multiple posts. Ask Dave what he suggests. Can you test over the winter in your area? I wonder why the former owner cut your 32s down to 16.25. Feel free to call me to discuss. 916 539-2540 California Time. Thanks Doug

Running out of time quick, cannot really feasibly test as once i am winterized it stays that way. The 31 herings sound inviting.

Doug I may be interested in a set of your Mercury 4 blades. What diameter do you have? Anything in the 17-1/2" range?

Thanks
Jim