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Mounting BF225

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AKnewbie

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My boat measures 27 inches from the top of the transom to the bottom. I have a 30 inch shaft length on a BF225. If I mount the engine using the bottom holes, the engine will sit 3 inches up off the transom and the cavitation plate will be even with the bottom of the boat. Is it OK to mount the engine like this?? I spoke with a nearby outboard shop and they said they sell an aluminum bracket that sits on top of the transom to raise the motor so a 30 inch shaft motor can be used in place of a 25 inch shaft. I did not know if the outboard needs to be resting on the transom or not. If anyone has answer, please let me know. Thank you
 
The rule is that the anti-cavitation plate should be even with the lowest point on the bottom of the hull. If you are offsetting the motor from the transom, with, say, a motor extension, then you raise the anti-cavitation plate one inch for every 12 inches of off set from the transom. Also, some folks will raise the cavitation plate one ince higher than the lowest point on the hull for every 10 mph above 40. Since I've never owned a boat that exceed 40 mph, I can't say how well that works.

Just as importantly for that engine, the exhaust ports must remain at least 5.9 inches above the water line, at rest.

When cruising, the anti-cavitation plate should be riding just on top of the water coming off the hull.

It really shouldn't matter how high the engine rides above the transom, as long as the anti-cavitation plate is where it is supposed to be and the engine mount is centered on the transom and your boat is rated for 225 hp or higher.
 
Thanks. My boat has an outboard well, not a bracket or swim step extension. I was wondering if it is OK to use the bottom holes in the stern bracket on the outboard when mounting it so it raises it up 3 inches off the top of the transom. I didn't know if this creates too much stress or torque on the transom with the motor sitting up that high. The Honda Shop Manual states you can "raise the height of the motor by using lower holes in the stern bracket", but it does not say if using the bottom holes is recommended. So, I was wondering if anyone knew anything about this.
 
I run a 225 Honda on my SeaCraft23 WA and the motor is raised about 2 inches above the transom. Your transom is what does the support and raising the motor is just part of setting things up to run right.The shop had originally mounted the motor sitting on top of the transom, but I was getting a porpoising effect. I also went to a Power Tech 4 blade stainless prop designed to raise the stern of the boat. This has worked out for me and I am assured that the exhaust is out of the water and the porpoising is gone. These motors create a very big back wash when powering down to come off plane.
 
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