Boat Builder Central - Builder Forums

She looks beautiful. Congratulations.

Testing how she corners at speed. I added a small skeg. I feel like it has made a huge difference to the steering and handling. It’s much easier to manoeuvre at low speed - and no tripping at high speed either.

TomTom wrote: ↑Sat Jan 08, 2022 11:41 pm [bbvideo]https://i.imgur.com/snGVhOo.mp4[/bbvideo]

Testing how she corners at speed. I added a small skeg. I feel like it has made a huge difference to the steering and handling. It’s much easier to manoeuvre at low speed - and no tripping at high speed either.

That makes me dizzy!

Great video! Thanks for posting it.

Looks great TomTom what speed were you at?

Tom

TomW1 wrote: ↑Sun Jan 09, 2022 7:41 pm Looks great TomTom what speed were you at?

Tom

Not far off 40 mph going into the turn, obviously it then bled off. I am definitely a fan of a small skeg now.

Another interesting thing is that at 2000 rpm I get 6.7 kts with a friend standing behind the console - but if they move fwds it picks up to 7.4 kts. Quite a difference.

I have a place for a fuel tank in front of the console… I think that will help the balance at trolling speeds.

Yep Tom the two tanks were part of the original design. Go for it. Just put a Y valve where you can reach it at the main fuel line so you can switch tanksi and keep fresh fuel in each.

Tom

TomW1 wrote: ↑Mon Jan 10, 2022 2:12 pm Yep Tom the two tanks were part of the original design. Go for it. Just put a Y valve where you can reach it at the main fuel line so you can switch tanksi and keep fresh fuel in each.

Tom

Might as well try and keep something original!!

TomW1 wrote: ↑Sun Jan 09, 2022 7:41 pm Looks great TomTom what speed were you at?

Tom

TomW1 … a couple of questions … all I can find on the prop is 17- N … it is a stainless 3 blade. Does this mean anything?

Could the size numbers be hidden by the hub?

Now I am getting a max RPM of 5400 … on a 2012 Yamaha F150 BET … (it’s a digital tach).

Is this about right?

Should I consider lifting the engine a notch or two? There is no cavitation or slipping in turns.

This might take it above 5500 rpm which is the max operating range … but wondering whether it is worth playing with this and propellers. And how much difference this can have.

Would a 4 blade stainless for example be able to drop my trolling rpms and get me the same speeds at around 1500- 2200rpms?

Hi Tom did some research on your Yamaha 2012 F150. Your prop pitch is to big if you are only getting 5400rpm's at wide open thottle. Max rpms for that motor per Yamaha is between 5500 and 6000rpm's for best top speed and longevity of the motor. The 5400rpms you mention is below the operating at max rpm and you need to reduce the prop diameter. As for the prop do you know who made it. The 17N stands for 17 New, what you don't have is diameter. It should be around 14 3/4-16" according to my prop catalogs for your motor. So, if you can find the diameter you will want to go down to a 15 pitch. You can measure the diameter also by taking a tape/ruler from the center to the furthest edge of one of the blades and multiply by 2.

As for lifting the motor if the large cavitation plate is within an 1" of the keel, don't bother with it right now. Let's worry about the prop for now.

Now as far as a 4 blade vs. a 3 blade I tend to recommend a 4 blade for people running offshore boats. A 4 blade helps make steering easier, maintains water contact better in rougher water and a couple of other reasons. But we need to know what 3 blade to fit on your boat before we can fit a 4 blade. Usually, I go down 2 pitches from a 3 blade for a 4 blade.

Well hope this helps. Let me know if you need anything else.

Tom