Originally Posted by win-or-bin
Cheers, will check the prop this afternoon, just didint think changing the pitch a bit would give me my missing 10knots! What should the max revs for a 50hp 2 stroke be? i thought if it reved to 7k it should go to 7k under load as well?
Thanks for the advice and help
If you give it wide open throttle in neutral it will probably achieve 14,000 rpm briefly before a large chunk of piston flies out the sideDont do it again naughty boy!
You want the RPM to be roughly in the 5000-5500 range, but there is no strict rule , just because an engine can rev safely to 5700rpm does not mean it develops maximum power at thet RPM. Power may peak before that. This allows you to under prop slightly so that when the boat is unloaded your rpm is slightly over the optimum, and as you load the boat if falls back towards max power. This way there is less difference between loaded and unloaded. As suggested try trimming up a hole at a time and see how that affects things. When i look at video of me flat out i am always surprised just how far the engine is trimmed out. you wont be able to trim for max top speed with manual trim as it will probably ventilate in turns and at takeoff , but you can find a good compromise between "bite " and speed. Also worth noting the first time i took my SR out i got 26-27 knots and was disapointed, the sea was not rough only a slight chop, next time out it was like a millpond and i saw 34.9 knots. conditions make a BIG difference to some boats. i am rambling again