A Photo & Discussion Forum for Wharram Design Enthusiasts
Is at 25hp too big on a tiki 30? I am considering powering my tiki 30 with a 25 so that i can also use it on my rib. I was just wondering if the extra hp will cause any problems other than increased gas consuption.
Thanks for any input
No, 25hp is not "too big." However, if you plan to use this engine on your RIB, you will most likely need to lower the engine well on the T30 since it is designed to have a 9.9 sail drive 25" shaft engine on it, not a 15" shaft dingy engine. Also, the 9.9 sail drive engine has a different gear ratio and high thrust propeller, making it efficient at slow sail boat speeds, whereas the 25hp engine is designed to operate efficiently at higher speeds.
Your insight is always helpful!
Friend put a 25 hp on a T 46, it was also a reasonably clapped out 2 stoke. I didn't hope for much, but the thing ran at considerable speed. I don't see a problem on a 30, they run those things on tiny skiff, so long as you can get it in the water. The thirty being much smaller will certainly move out in front of the prop, more easily than a 46. On the other hand, if you have something classic like a Yam 25 2 stroke, that runs good, you can sell it for a lot, and maybe get the motor you actually want for not much more.
Yamaha makes the 25hp with a 20" shaft. You can put a 5" extension on from Bay Manufacturing. They have built these extensions for many years. The gearing can be compensated for with prop pitch. With only a 20" shaft corrosion will eat your motor quickly. On my first Tiki 30 my first engine mount was too low. The motor pod was too low. I had many problems with corrosion. I raised the motor 6" and that was much better. The newer outboards have rev limiters and if the prop catches air the motor will not overrev and will grab the water again immediately. The older motors would catch air and rev wildly and not grab water until the throttle was backed off. It was a long trip up the Baja coast once with an outboard on a transom bracket on a 30' ultralight mono.
I use one yamaha 20hp 4stroke in one holliday. My original motor is one 9.8hp 4stroke. The yamaha only consumes more gasoline, and the boat goes little faster( my motor 6,5 to 7 knots, yamaha 7 to 7,5 knots).
I think the best for tiki 30 is yamaha 9,9 long shat, eletric start and comands