Interesting problem...
 

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.

Interesting problem...
 

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.

Interesting problem...
 

On Sun, 26 Jul 2009 21:45:54 -0400, J i m
wrote:

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.

We did - he's lighter than I am, but we both sat on the front deck -
didn't help.

Interesting problem...
 

"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

Interesting problem...
 

On Jul 26, 9:00*pm, "Eisboch" wrote:
"J i m" wrote in ...



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

Not an expert in such, but I was going to say . I think the guy needs
a jack plate.

Interesting problem...
 

On Sun, 26 Jul 2009 22:00:22 -0400, "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.

Yeah - that was a thought. My own experience with jack plates would
seem to indicate that it would help more than hurt.

And as it happens, I have a mechanical jack plate sitting in the
garage.

Interesting problem...
 

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.


The engine is mounted in the wrong set of holes, maybe. It's also a lot
of engine weight for a 20' boat.

--
Whatever moral rules you have proposed, abide by them as they were laws,
and as if you would be guilty of impiety by violating any of them,
*unless* you are a conservative Republican office holder or minister. If
that is your position in life, then anything goes.

Interesting problem...
 

"Wizard of Woodstock" wrote in message
...

On Sun, 26 Jul 2009 22:00:22 -0400, "Eisboch"
wrote:

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.

Yeah - that was a thought. My own experience with jack plates would
seem to indicate that it would help more than hurt.

And as it happens, I have a mechanical jack plate sitting in the
garage.


In my case, a jack plate wasn't required. The bolts holding the engine on
the transom were removed with the engine strapped to a fork truck. It was
either lowered or raised (can't remember which) by one mounting hole and
reattached. It made a huge difference. The chine walking was scary on
that boat when making turns at high speeds and the porposing was obviously
annoying. The motor height adjustment completely eliminated both. It
didn't take much.

Eisboch

Interesting problem...
 

On Mon, 27 Jul 2009 05:48:00 -0400, "Eisboch"
wrote:


"Wizard of Woodstock" wrote in message
.. .

On Sun, 26 Jul 2009 22:00:22 -0400, "Eisboch"
wrote:

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.

Yeah - that was a thought. My own experience with jack plates would
seem to indicate that it would help more than hurt.

And as it happens, I have a mechanical jack plate sitting in the
garage.

In my case, a jack plate wasn't required. The bolts holding the engine on
the transom were removed with the engine strapped to a fork truck. It was
either lowered or raised (can't remember which) by one mounting hole and
reattached. It made a huge difference. The chine walking was scary on
that boat when making turns at high speeds and the porposing was obviously
annoying. The motor height adjustment completely eliminated both. It
didn't take much.

I'll have to take a look at where it's mounted on the engine bracket.
It's a short shaft, so I imagine there isn't a lot of room to play
with.

Interesting problem...
 

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.