Eisboch wrote:
"J i m" wrote in message
...
Wizard of Woodstock wrote:
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.
Try putting 100 pounds of weight at the bow and see if that helps.


I had a Robalo that handled like that. No matter how I trimmed it, it
porpised and chine walked in turns. I mentioned it to a guy at work who
took it and adjusted the mounting height of the engine on the transom. All
the porposing and other squirrely handling symptoms disappeared.

Eisboch



That was my first thought. You could also try a small jack plate.
Here's an example:

http://www.bobsmachine.com/

Email them - they are very helpful. They told me I wouldn't gain much
on my bass boat (alum w/90HP) so they seem to be honest people and they
have been around a long time.