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[email protected] gfretwell@aol.com is offline
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First recorded activity by BoatBanter: Jul 2007
Posts: 36,387
Default My 1985 Mercury 75

On Mon, 23 May 2016 11:59:45 -0400, Justan Olphart
wrote:

On 5/23/2016 11:33 AM, Ryan P. wrote:
On 5/23/2016 10:06 AM, Justan Olphart wrote:
On 5/23/2016 10:46 AM, wrote:
On Mon, 23 May 2016 08:33:24 -0500, "Ryan P."
wrote:

On 5/17/2016 1:48 PM, Ryan P. wrote:

There was great debate over whether to lower the engine a peg, since
now it sits a little higher when vertical, but with the additional
setback (about 7") and additional down tilt, we figured the water
would
be quiet enough to give me good performance. I can always lower it a
notch if I don't like the way it performs this weekend.

And the answer is... I don't like the way it performs. Oh, it gets on
plain super fast, but now I have a HARD pull to the right. I know I
should be able to tilt the motor back up to about vertical, but now at
cruising speed, vertical brings the prop up too high and I get
excessive
revving.

Am I right in thinking that the hard pull is because the motor is
tilted in too far? Will lowering the motor a inch (or two) actually
alleviate the problem by letting me tilt out farther?

Thanks!

Have you tried adjusting the trim tab?

That might help but I suspect he's getting bow steer. He needs to lower
the motor and make sure he has some bow lift and the bow wake starts
about 1/3 of a boat length from the bow. Once he has that he can tweak
for the performance he wants.


So that being said, if I had neutral steering before I added the 7"
setback from the power tilt unit, Do I need to drop the motor down 1" to
make it equal with its height prior to the modification, or do I need to
drop it farther?

There's no formula. It's all trial and error.


I usually use a sharpie pen and mark which way it was pulling at each
adjustment I try. After a few tries you can get a pretty good guess
which one is the best compromise. I usually want it nulled out at
around 4000 RM add the best trim.