After two days on the water with my new sib I think I adjusted everything right, but at top RPM the prop seems to loose grip.
When I quickly go to full throttle the prop quickly goes to full RPM with little Thrust. I do not get any bow rise
So I accelerate slowly. With two on board I can reach about 38kph like this, at full throttle. But the engine seems to be 1000rpm under max.
Now if I jump a small wave or take a corner too hard, so the prop catches a bit of air, it sometimes happens tat rpm goes up about 1000rpm to full rpm, but speed stays the same. (does this condition harm the engine?) Then I have to reduce throttle and accelerate again to have grip.
I have a 30hp selva 2stroke. There is a number 13 on the prop. Boat a 3.8m SIB with 150KG load.
With such a well powered engine on such a small boat, does it sound right to you to go for a 11 pitch or should the problem be somewhere else?
Boat is well balanced, Engine timed to the second hole (third rooster tails). Increasing engine height 25mm reduced splash and drag. I had trim tabs installed, but found with a well balanced boat they just cause drag, so I took them off for now.