F225 Mounting Height

Looking at the performance bulletin from Yamaha for my set-up they listed mounting height as #2; there are four mounting holes on the motor so do they start with #1 on the bottom or top of the holes.

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Looking at the performance bulletin from Yamaha for my set-up they listed mounting height as #2; there are four mounting holes on the motor so do they start with #1 on the bottom or top of the holes.

Forget the holes for a moment !
The underside of the cavitation plate should be level with the bottom of the hull ! this is a good starting point on any boat ,as little as 1/4 of an inch can make a differance to performance and steering !!

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The underside of the cavitation plate should be level with the bottom of the hull ! this is a good starting point on any boat ,as little as 1/4 of an inch can make a differance to performance and steering !!

To find out if its the right height and suited to your boat and your way of driving is at about 3/4 throttle gently start to turn in a circle gradually getting tighter and tighter until you are on full lock , if you do not experience any cavitation then its right , You need to do this in both directions port and starboard .
If you do get cavitation then the motor may need to drop maybe 1/4 of an inch only.
ALSO at just over the same throttle setting gradually adjust the trim up from the down position till you feel the boat pick up speed without actually touching the throttle ,Take note of the position on the trim gauge dial because thats your optimum trim angle as well !!
Hammer down and see what she'll do !! When all's well it should be as light as a car to steer and drive !!
I recently changed from cable to Hydraulic steering, the change is one finger steering against always having one hand to hold it straight .

My cavitation plate is above the bottom of the hull, which I unstand is acceptable to a certain degree.

Excessive cavitation was the problem I was having. My motor was mounted as high on the transom as it would go so last night I dropped it one hole. Can't make adjustements smaller than that without a jack plate so I'll have to see how that does, if it's to much of an extreme change I'll have to look at installing a jack plte to allow for fine tuning.

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My cavitation plate is above the bottom of the hull, which I unstand is acceptable to a certain degree.

Excessive cavitation was the problem I was having. My motor was mounted as high on the transom as it would go so last night I dropped it one hole. Can't make adjustements smaller than that without a jack plate so I'll have to see how that does, if it's to much of an extreme change I'll have to look at installing a jack plte to allow for fine tuning.

Just try the procedure i described before , it theres any cavitation then the motor is still to high !.
If you use a good long straight edge you can get it right But a jacking plate would do wonders and give you that finer adjustment .As i said just a 1/4 of an inch is all thats needed in a lot of cases . Has the motor got any set back from the transom ?? With set back the motor can be raised slightly , One foot set back and the motor can be 1/2 inch above the level of the hull safely! so if you are going to look for a jacking plate get one with set back as well and get the advantage of the two . Set back will make the trim more responsive to the touch !!and a fraction more speed and better handling