Originally Posted by smithash
I have a honda 3.2 airdeck and a yamaha 9.9 standard shaft 2 stroke (actually is been upgraded to 15hp) my question is is this the correct shaft length for the boat.
The reason being that last year I used the boat on Lake Garda and experienced a lot of cavitation etc which I never had with the previous engine a 8hp Yamaha 4 stroke.
There is some slight chipping on the prop which I will replace this summer but any info welcome as I have searched the honda sites to no avail
I have owned a Honwave T32 and it was a great boat, I used mine with a Mercury 15hp 2 stroke short shaft which weighed 37kg. I had no cavitation problems with that setup, however when I changed the boat to the larger T38 I experienced exactly the same problems your having.
Now I may get shot down in flames, but I think because the boat is setup for the much heavier 4 stroke Honda's the boat has "too much" bouyancy at the rear and is lifting the prop up out of the water.
The only thing I can suggest is try moving the fuel tank and any other gear to the back of the boat to keep the back down.
Hope this helps.