A Photo & Discussion Forum for Wharram Design Enthusiasts
I have the outboard off the the aft beam and off-centre. I works ok and it give's me a clear cockpit. As Kenneth said the better from the cavitation point of view is when the outboard is in the center of gyration, but it puts the motor in the cockpit, near the mast. I like my clear cockpit and prefer not to have anything fixed in it. Sometimes I have cavitation problems, but usually it disappears when I change direction a little or decrease the velocity. I still prefer the clear cockpit than putting the ouboard on it, but I suppose it is a personal matter.
Thank you for the reply and info. I would think that the further aft the engine is the better the maneuverability?
Andrea's I am wondering what are the advantages if you mount the engine off center.
I think that at a low velocity the further aft the engine could be better, because you have a greater lever arm. But I have no other boat to compare and when I bought her the engine was in this position.
The motor is a little of center and in this position it clears the main sheet (I suppose is for this reason that the motor is of center). When there are waves it is important to raise the motor as high as possible, so it don't slam. Also you have the tiller of the motor near one side of the cockpit, so it is closer to one of the seats. On the other hand, you have a good side and a bad side of the cockpit to work on the motor. In practise it doesn't have been a problem to me because the cockpit is free of obstructions so I can change very quickly my position.
The manueverability of the aft engine mount is unmatched... Gave up trying to post, what changed?
Patrick, I went from a long-shaft 20" motor to the extra long-shaft 25" motor and cavitation is nil...Of course, the prop is at the same level as the deepest point of the keel, which is where you want it to be! Pushes the boat better that way.
Patrick, it's the Nissan (rebadged Tohatsu) 4-cycle 6hp SailPro model. The SailPro comes with the lower pitch, wide-blade prop designed for displacement boats. It weighs in at 55 lbs/25kg. The 9.8, depending on its age, could weigh considerably more. You don't want too much weight hanging on the aft end of the tiki. In flat water, the 6hp gets my lightly loaded t26 to 7 knts + at less than full throttle. In chop it's slower, but with judicious steering, ie, not trying to power straight at the swells, it still pushes the boat well.