The prop that came with the engine has turned out to be too wee* - so both exceeded max RPM & let go in the lumpy stuff with way too little provocation.
So, at the weekend I managed to fit my old Yam G series from my old super torquey 55 that used to live on the transom. It was up an inch of pitch, but also up a good 3/4 inch on diamater.
Needles sto say the "grip" was faultless, but it took a substantial few RPM off Vmax. (as expected) Leaving me way too over propped. (1000 -ish rpm drop!)
So, having had a peruse through the G series listing, does anyone have one or more of these (or Merc equivalent) lying around that I could borrow for a quick test?
1) 13P x 10_3/8 dia "standard Alu" PN 6H5-45945-00-00
2) 13P x 11_1/8 dia "standard Alu" PN 69W-45945-00-00
3) 14P x 10.25 dia "standard Alu" PN 6H5-45958-00-00
4) 13P x 10.5 dia "performance" PN MAR-GYT3B-03-13
5) 14P x 10.25 dia "painted Stainless" PN 663-45930-00-00
These are listed in "catalougue order". My preference at the moment is: 4, 1 <3 or 5> then 2.
2 is an inch down in pitch version of what I tested on Saturday, and even if I drop pitch to 13" in theory should still only just get me to the bottom end of the max RPM band (and I was fairly lightly loaded on Sat).
Can anyone help with a loan of one for a couple of hours or sell one in any sensibly workable condition at "test prop price"?
If it's a loan prop and you are in Central(ish) Scotland I could bring the boat to you if you fancy a wee cruise in company at the same time.
*technical description - read "too small pitch or diameter"