25HP on a 4.5m SIB - speeds?

MrHeadsocket · 28 September 2014, 17:27

Hi guys (and gals).

Following an awful start to my first venture with a boat when I was missold a 15HP Mariner, I have managed to win an auction of a 25HP Johnson and will hopefully be collecting in next weekend. My question is, what sort of speeds would I get with a 4.5m SIB (Ali floor), 25HP with 4 adults and about 15kg of kit? Will it plane? The max HP on the transom is 30HP so 25HP will do nicely! Cheers in advance!

MrHeadsocket · 28 September 2014, 18:44

Also, what speed with 1 person and 15kg of kit? Cheers

Mikefule · 28 September 2014, 20:27

It should certainly plane 4 up. As for the max speed, that will depend on lots of variables. It sounds like it should be a nice set up - plenty of space and enough power to have fun.

chriswood · 28 September 2014, 20:49

Hi - I have a 3.8 Ali floor Sib with a 30hp and it gets on plane really easily with 2 adults, 2 teenagers and a child. With me and my 9 yr old daughter - not sure of speed as never tried to measure it but its very quick. Hope that helps!

bingosucks · 28 September 2014, 21:36

i reccons you`ll hit 20-25 thats a big sib, you will find shes more responsive with a bit of weight

tehguy · 02 October 2014, 17:10

My 3.9 hit 28 knots in the calm with 25hp and 3 up. You should plane no problem!

MrHeadsocket · 06 October 2014, 16:08

Thanks for the replies! The 25HP I was going to get fell through, but I currently have a 15HP that I may be getting rebuilt and in the process uprated to 20HP. What sort of speeds etc would I get with a 20HP and 4.5m SIB? Cheers in advance!

Poly · 13 October 2014, 10:38

Quote:

Originally Posted by MrHeadsocket

Thanks for the replies! The 25HP I was going to get fell through, but I currently have a 15HP that I may be getting rebuilt and in the process uprated to 20HP. What sort of speeds etc would I get with a 20HP and 4.5m SIB? Cheers in advance!

20 knots ish (ie. +/- 3 knots).