setting up merc height

[jims3000]

was wondering how low in the water does the foot need to be to get the best performance?

 

[Guest]

Mount the motor with the cavitation plate even with the bottom of the boat or as close to it as possible then you will have to try different props to get the best performance out of the motor.

 

[jims3000]

thanks for the info. i guess im going to have to get a jackplate

 

[hl&s]

There's some good info on the Merc site.

http://sites.mercurymarine.com/portal/page?_pageid=126,49901,126_49907&_dad=portal&_schema=PORTAL

 

[jighead]

give us a little more info like boat brand, length and weight, motor h.p.,set back if any

 

[jims3000]

it a 1986 astroglass 17.5 bass boat 1985 merc 150hp bolted to the transom and a 23 pitch prop.i was going to change prop to get the rpms up and the marina told me to check my rpm and look at my rooster tail the rooster tail should be as high as the motor.i told him my rpm was 5200 and it didnt realy throw a rooster tail he said to raise the motor one hole and that may solve my problem .the water holes on the motor are almost even with the bottom of the boat and i dont want to go much higher and loose water pressure but i also want the best performance too.

 

[jighead]

you should be able to raise one more hole and be ok.just keep a watch on your h20 pressure. if your pressure drops ,drop your motor a notch

 

[Guest]

Whoever you have been talking to is full of you know what when he said to watch for the rooster tail. If the motor cavitation plate is even with the bottom of the boat. If you have a jackplate it makes it easier to fine tune the motor to the boat. Watch your rpm's, don't ever go over wot, the motor was designed to run at a certain wot, going over this rpm will eventually blow your motor up. Rooster tails have nothing to do with motor and boat performance. Take this with a grain of salt or go by the experts opinions you have been talking to. It is your boat and your motor and your money.

 

[Bubbakat]

That Merc site is a good informative site.
The rule of thumb is Like Doc1 said set the anticavation plate even with the keel of the boat or no more then 1 inch above the keel. If you are running a jack plate or after market T&T then this is going to set the motor back some . That will allow you to raise the motor 1 more inch. You are allowed 1 inch rise for every 5 to 6 inches of set back.