2 x 250hp props?

kelvin · 14 June 2009, 17:15

Just fitted 2 x 250hp 2 stroke yamahas to my 8.5mtr tornado with standard 19" props. i get 48.5knts top whack trim up, but the engines seem to be over reving at 5800rpm. thinking of going for the next prop up as the engines do not seem to be working hard just revving high.
i did have 2 x 200hp with the same props doing 44.5knts full chat at 5200rpm.
as a working boat my aim is not top end so much, but i do do regular 100 mile round trips so speed is of an essence.
any advice????

Chris · 14 June 2009, 17:56

If you went up to 21" props you would bring your RPM down to about 5500 I should imagine you would be good for 52 knots as well

codprawn · 14 June 2009, 22:22

And you would save fuel when cruising.

kelvin · 15 June 2009, 19:01

any other suggestions besides yamahas 21"? someone said quicksilver do a good 4 blade for this unit

codprawn · 15 June 2009, 23:13

Solas Titan 4 blade.

http://www.steeldevelopments.net/erol.html

May be worth sticking to a 19" if you go to 4 blades.

stepheneyre · 15 June 2009, 23:25

hi
i used a 19 p prop this year bought myself a 23" prop what a difference
try this link
http://www.streamlinedpropellers.co.uk/contact.html

i phoned up very helpfull and good prices also look on e bay for them

ta

steve