This year I installed a Garelick lifter for my Yamaha 9.9 high thrust 4 stroke.
It is a
somewhat heavy (100 lb.) engine, and thus the necessity for an assisted lifter.
What
I did to support the engine was buy a big piece of stainless steel plating,
which I used
as a backing plate for the Garelick. This distributes the load across a larger
area of the transom.
As far as the mounting height, if you go to the Garelick web site or one of
their vendors, you will
find some mounting instructions. I also was worried about the engine hitting
the transom when
fully tilted up. I solved this by introducting some hardwood shims between the
bracket and the
transom to move the engine further astern. I have the long shaft engine, so I
got the Garelick
with the greatest lift height (about 11 inches, I believe). You then have to
position the bracket at
the height on the transom which will get the prop low enough in the water for
rough
following sea conditions, yet high enough to lift it clear of your transom. The
Garelick has 4 lockable
positions for setting the height of the engine for various sea conditions.

Hope this helps,

Sherwin D.

" wrote:

I would like to know some info about Yamaha 8hp High Thrust 4-stroke
outboard motor when it is fully tilted up.

I am planning to get that Yamaha motor as a kicker for trolling and
backup. Unfortunately, I cannot mount it directly on the transom of my
boat. The reason is that the transom only has one opening for the main
motor. The boat has a container in each side of the opening. I cannot
mount the motor over the container because the container is a flimsy
structure. I will have to somehow mount the motor at the back of the
transom.

I could have installed a manual-motor-lift (such as the one from
Garelick); but I am looking for the version of Yamaha 8hp outboard
that has a power-trim function. This means instead of having the
outboard lifting straight up and down, I will have it tilting up and
down.

Seem like the best way is to install a motor bracket behind the
transom, mount the 8hp motor on the motor bracket, and has the 8hp
motor kind of sticking out. The question is how far that I should have
it sticking up. If it is not sticking out far enough, the cowl of the
motor will hit the container that I mentioned above when the motor is
fully tilted up. If it is sticking out to far, I am afraid that it
will add too much stress on the transom. I want the motor bracket
sticking out just far enough not to hit the container when the motor is
fully tilted up.

My questions a
1. What is the distance between the far end of the cowl and
the motor mount when the motor is fully tilted up?
2. Any downside of doing this?
3. Any better idea?

Thanks in advance for any info.

Jay Chan