Gilgamesh2012
Recruit
- Joined
- Sep 13, 2012
- Messages
- 3
Hi,
I have a 5,5mtr (18ft) console boat weighing about 550kg (1212pounds). I've run tests with four props with only myself on board (88kg/194pounds). The outboard is a 50HP Honda BF50A from 2006.
The goal for getting a new prop was to gain a better hole shot as I would like to take up kneeboarding or wakeboarding and also with some guests on board getting on plane is not possible or very difficult (4 adults + 5 kids <10yrs). When someone is sitting at the transom getting on plane is very difficult.
My prop dealer recommended a Mercury spitfire prop to gain a better hole shot. So, initially, I went from a 14P 4-blade Honda alu prop to a 12P Mercury Spitfire prop. The 14P didn't get me past 5600rpm at WOT, but the 12P resulted in an unexpected increase to 6300rpm. So I tried a 13P mercury spitfire, which resulted in minimum decrease in rpm (6200).Finally I tried a 14P mercury spitfire which got me at 6000rpm. Though the merc 12P did have a noticeably better hole shot compared to the Honda prop it's hard to measure differences between the three merc props.
At the advice of the dealer I entered my results in the prop calculator and came to the conclusion that the merc props give me ~22% slip. So one question I have is whether this is caused by the relatively heavy boat with a 'ligth' outboard, or that the prop design is the cause, or maybe something else?
Apart from slip, I need to decide on the 13- or 14P prop. The 13P probably has better holeshot but it exceeds 6000rpm when loaded lightly, or the 14P that offers 6000rpm, but I'm unclear what the effect on holeshot is compared to the 13P. The currently the weather/temp does not allow us to just try kneeboarding, which would obviously be the best test.
Yesterday I was able to try the 14P with crew and depending on weight distribution I reached WOT at 5700-5900rpm.
With the goal in mind, which prop would you choose?
/D
I have a 5,5mtr (18ft) console boat weighing about 550kg (1212pounds). I've run tests with four props with only myself on board (88kg/194pounds). The outboard is a 50HP Honda BF50A from 2006.
The goal for getting a new prop was to gain a better hole shot as I would like to take up kneeboarding or wakeboarding and also with some guests on board getting on plane is not possible or very difficult (4 adults + 5 kids <10yrs). When someone is sitting at the transom getting on plane is very difficult.
My prop dealer recommended a Mercury spitfire prop to gain a better hole shot. So, initially, I went from a 14P 4-blade Honda alu prop to a 12P Mercury Spitfire prop. The 14P didn't get me past 5600rpm at WOT, but the 12P resulted in an unexpected increase to 6300rpm. So I tried a 13P mercury spitfire, which resulted in minimum decrease in rpm (6200).Finally I tried a 14P mercury spitfire which got me at 6000rpm. Though the merc 12P did have a noticeably better hole shot compared to the Honda prop it's hard to measure differences between the three merc props.
At the advice of the dealer I entered my results in the prop calculator and came to the conclusion that the merc props give me ~22% slip. So one question I have is whether this is caused by the relatively heavy boat with a 'ligth' outboard, or that the prop design is the cause, or maybe something else?
Apart from slip, I need to decide on the 13- or 14P prop. The 13P probably has better holeshot but it exceeds 6000rpm when loaded lightly, or the 14P that offers 6000rpm, but I'm unclear what the effect on holeshot is compared to the 13P. The currently the weather/temp does not allow us to just try kneeboarding, which would obviously be the best test.
Yesterday I was able to try the 14P with crew and depending on weight distribution I reached WOT at 5700-5900rpm.
With the goal in mind, which prop would you choose?
/D
