Mounting motor

[Bwalker]

I just bought a new Yam 70 to mount on my new Duck boat. Any one have any tips a to how best accomplish this in regards to height, etc?

 

[Dhadley]

Re: Mounting motor

Your final X dimension depends on what prop (type & brand) you plan on using and how it reacts with that hull. If youre planning on using a standard Yamaha ss prop you can probably start with the AV plate about an inch up from the true bottom.

 

[Bwalker]

Re: Mounting motor

I plan on using a Yamaha aluminum prop. How will I know when the motor is mounted at the correct height?

 

[Dhadley]

Re: Mounting motor

Testing. If the rpms are too low and the prop doesnt vent, you can go higher. If the prop vents but the rpm is OK, you can go down slightly. If the rpm is too high, you can go to more pitch.<br /><br />If the rpms are where you want them and it doesnt vent, youre good to go. We have to find another excuse....er....reason to go boating.

 

[Bwalker]

Re: Mounting motor

I assume by vent you mean cavitate. Like what happens when you have the motor trimmed up to high.

 

[JasonJ]

Re: Mounting motor

Cavitation is when small air pockets develop at the propeller blade, becoming superheated, and causing actual damage (pitting) on the blade surface. Venting is when the propeller loses its bite in the water, two different animals...