Yamaha High Thrust and Merc Pro Kicker

[linweir]

I have a yammy 8 HP high thrust 4 stroke kicker (T8) on my boat. I believe Yammy High-Thrust uses a modified prop to generate more power.

However, I want more power to push my boat faster. Current speed is 4.5~5 Mph under this T8.

I plan to upgrade to Merc pro-kicker 9.9 HP.

Wonder if it can improve alot?

[irishfield]

It won't improve top speed at all... 4.5 to 5 mph is "Hull speed" for the boat. If the motor doesn't have the power to put it on plane.. that is the best it's going to do.

[capt bruce]

What Irish said . want more speed get a twenty than maybe you can get the boat to plane .

[linweir]

Txs guys.

I think I may trade in another 15 HP yammy instead.