Prop

[HMJB]

Hi

Got a run out in my new boat yesterday

Humber 5.3 Destroyer - 2006 Yamaha 75 2 stroke.

It is fitted out with a single jockey / console and 2 x twin jockeys behind and we had 5 of us on board 2 x adults and 3 x children all under 10 so quite small.

Went from Hamble Point to Cowes and back for lunch and was fairly windy / typical short solent chop on the way over, but much calmer on the way back.

Managed to open it up and was getting just over 30knts - there may have been some tide. Was pleased with that, as knew the 75 was underpowered when fitted it, but had it from an old boat. Will hopefully upgrade it to a 90 next winter.

The prop is marked SSI 13X19-K. At full throttle engine was only at circa 4,600rpm, so imagine it is propped incorrectly (is just the prop I had on from my last boat, which was lighter).

I am not looking for any extra speed and know the boat is underpowered, but wandered if propped correctly would it have better hole shot / mid range / economy? And be better for the engine to function as it was meant to - ie through all the rev range?

Any help / previous experience with a similar set up much appreciated.

Thanks

Hartley

[GARYSHORT]

You have to decide if hole shot, top-speed, or best of both worlds is more important and then prop accordingly. Most RIBS don't need hole shot performance unless you are skiing/tubing, or are using in surf conditions where you need instant power/plane performance. If you are going long distances (more than a few KM/Miles, then a speed prop would be best.

I have a mid range to get the best of both worlds and happy with that.

[Iankristy]

Correct prop will be better at everything but as above some will be specifically good at speed or economy or hole shot. Go onto yams prop calculator and see what it says [emoji106]

[HMJB]

Originally Posted by Iankristy

Correct prop will be better at everything but as above some will be specifically good at speed or economy or hole shot. Go onto yams prop calculator and see what it says [emoji106]

Thanks will have a look at the prop calculator and see what it suggests.

[69cmw]

PM Sent

[Locozodiac]

Question : will you always, frequently or once in a while be boating with 5 up with say a family orinted combo ? As of now that motor at wot is revving at the extreme lugging side of the min-max wot rpm range which is 4500-5500 K revs. That's 900 wot rpm under its max wot rpm range. Can increase the min-max wot rpm range going for at least an SS or Alum 13X17-K Yam prop from current installed one. Prop calculators only suggests starter props if your boat motor combo doesn't count with one. Testing on water it's a different reality..

Happy Boating

[HMJB]

Thanks - think I need to get a 17p and try that