On Mon, 27 Jul 2009 08:46:11 -0400, Gene Kearns
wrote:

On Sun, 26 Jul 2009 21:36:46 -0400, Wizard of Woodstock penned the
following well considered thoughts to the readers of rec.boats:

|A friend on mine just bought a used Stratos 20' bass boat with a 250
|Yamaha Vmax. He called this afternoon and asked me to take a ride
|with him because he couldn't get his boat to plane right.
|
|We met up at Webster Lake and took it for a ride after checking
|everything over - everything seemed to be working, nothing out of
|sorts with the hull.
|
|Got on the water and it's the oddest thing - no matter what trim
|position, the boat would porpise (pitch) at speed. Vary the speed and
|you'd get a yawing action - trim made no difference. No roll to speak
|of.
|
|All the bolts are tight, properly torgued, the prop is symmetrical,
|the skeg on the outboard is straight, keel is straight - no obvious
|repairs.
|
|Any ideas? I'll admit it - I'm stumped.

Given the available information, the only thing it *could* be is that
the motor is mounted too low.

Has it ever planed correctly? If so, what changed...

Don't know - it's a used boat, low hours Yamaha. We're going to take
it out again this morning. He owns a independant car repair place, so
we're all set with lifts and such.

I know on my Ranger, I had problems with the FICHT short shaft engine
on the 620 based hull - it was never quite right and just playing with
the fixed height positioning didn't solve the problems - some would go
away, others would show up.

It wasn't until I put the jack plate and 25" shaft engine that I could
really dial in the engine positioning to solve ALL the problems in
addition to gaining 6 inches in length which also helped.