I bought a 9.8 Tohatsu for my Hunter 26, the motor came with a mid range prop, I notice that at full throttle I get a lot of cavitation bubbles swirling in the prop wake, also the boat is only making about 5.8 kt, and the motor should push it along at over 6 ...?? should I go to the full displacement prop, or something in between..I figure some of you must have pondered this issue and found the best pitch, hope to plumb your knowledge..if it helps..the boat weighs in around 3 tons loaded and crewed Thanks for the help.
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robin, you *might* be a bit over-propped but

your theoretical max speed is ~6.4 knots. What are you using to measure speed with? If a paddle wheel, you may be .5 knots off anyway and your motor/prop is getting you to hull speed at less than full throttle. At any rate, maybe you could borrow a prop 1 pitch less or buy it with the understanding you could return it if unhappy. Same for BillP except if you throw that puppy into R and rev sharply, youll probably cavitate regardles of pitch.

Clark
Lake Guntersville, AL
05/08/06 at 14:31
Hunter 26

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I also have a new 4 cycle 9.8

Tohatsu on my 260. When I ordered the O/B it came with a mid-range prop. I ordered the prop for the heavy displacement and keep the orginial one as a spare. The combiation seems to work well, I just purchased a Tach and will see if the max RPM is reached at full throttle. Just for information sake I bought a 25 inch extra long shaft length. From what I know if the outboard reaches Max RPM at full throttle than you have the right pitch. If the max RPM is not reached that it is overloaded, if your RPM is higher than max RPM than you are over reveing the engine (also not good). For our engine 9.8 Tohatsu I remember only three props available. You pick the closes one to match max RPM at full throttle John USNret

LKYusnret
High Point, NC
05/08/06 at 16:38
Hunter 26