Capt John wrote:
On Jun 13, 3:18 pm, HK wrote:
trainfan1 wrote:
HK wrote:
I know someone considering the purchase of a 21' Parker center
console, the model with the 21-degree transom deadrise. The boat
itself weighs 2750 pounds. Great open fishing boat.
Parker recommends three Yamaha engines in its four stroke line: 150
hp, 200 hp and 225 hp.
For a boat with the same hull but with a pilothouse cabin that brings
the hull weight to 3250 pounds, the Yamaha performance page indicates
a top speed of 39.3 mph with the 150 hp engine running 5600 rpm and
burning 17.5 gph. At a cruise speed of 25.6 mph at 4000 rpm, the rig
burns 7.8 gph.
I'm recommending the 150 hp engine for the 21-foot center console. I'm
guessing a top end of 42-43 mph with a fuel burn of 15-16 gph, and a
4000 rpm cruise of of 27-28 mph, burning 6.5 to 7 gph.
I don't see any need to step up to a 200 hp V6 on this boat. The days
you can comfortably run more than 25 mph in a 21' boat are rare on
Chesapeake Bay. The 150 is about $4000 less than the 200.
Any comment on the extrapolations?
You're still going to have the engine running at 5600 rpm WOT, and
burning 17.5 gph, with a different prop, maybe.
I'm surprised the cruise engine speed is as high as 4000 rpm, but this
is a 4 stroke. It's also quite a bit of fuel at WOT for any stock 150.
No E-Tec options to consider?
I know... it's a Parker.
Rob
I doubt the engine will be running at 5600 rpm. No one I know wants that
kind of fuel burn.

We got a data sheet faxed from Parker. Their sheets are pretty reliable.

4000 rpm happens to be the sweet spot for these four stroke Yamahas. It
is on my 225, too.

The data sheet says 16 gph at 5600 producing 40.9 mph, and 7.30 gph at
4000 rpm producing 26.2 mph. That's pretty close to my guess
extrapolations. No reason to go to a 200 or 225 hp.

Naw. Not interested in an Evinrude eTec. I like four stroke engines.
So does my friend.- Hide quoted text -

- Show quoted text -

I wouldn't be so quick to toss the idea of a two stroke.

They weigh less, which is always a good thing on a small boat. Their
far less complicated, which helps for long term reliability and cost
of repairs/ownership. The fuel injected 2 stroke engines burn less
fuel. They cost less to buy, and you run them at lower RPM's than a 4
stroke to get the same power, so the 4 stroke is probably going to
wear faster. OK, you do have to add oil to a 2 stroke, but you have to
check the oil, change it and change oil filters on a four stroke. Is
the yard going to let you do that? So you've probably got to pay for
that, and we all know how inexpensive yard bills are. Two strokes have
been around for a long time, you know their reliable (I'd get a Merc
over the Yamaha any day),

Nothing really wrong with Yamaha except for where they're built & where
the $$ end up...

4 strokes are still new,

?

http://hometown.aol.com/homelite55/

Old technology, to some.


and new products
have their problems. I wouldn't even consider a 4 stroke, especially
on a small boat. My two cents.

They have their place at times, but the 2 strokes are getting so good so
fast now.

Rob



John

On Thu, 14 Jun 2007 09:22:12 -0700, Capt John
wrote:

They weigh less, which is always a good thing on a small boat.

Not significantly. It's generally at or around 100 lbs depending on
model.

Their far less complicated,

That is absoutely not true, unless you consider the Yamaha carbed
series as "uncomplicated" which they are not.

which helps for long term reliability

That's true enough in particular with today's oil injection/metering
systems.

What also helps long term reliability is new materials science and
just like four strokes, good service and maintenance regimens. Also
the new synthetic oils also help, but they are expensive.

and cost of repairs/ownership.

Eh. Repairs are as expensive as four strokes in terms of labor and
depending on what kind of two stroke (carbed vs injected) parts are
expensive no matter what kind of power system.

The fuel injected 2 stroke engines burn less fuel.

Mine does and is probably the most efficient two stroke on the market.
Yamaha HPDI are pigs on gas and Optimax engines aren't that far
behind.

They cost less to buy, and you run them at lower RPM's than a 4
stroke to get the same power, so the 4 stroke is probably going to
wear faster.

Eh - that's a problematic statement. Mine is a 90 degree engine block
with a lower gear ratio than Yamaha/Merc which is what produces the
power (plus a four blade prop).

OK, you do have to add oil to a 2 stroke, but you have to
check the oil, change it and change oil filters on a four stroke.

That's one area where we agree.

Is the yard going to let you do that? So you've probably got to pay for
that, and we all know how inexpensive yard bills are.

That's a very good point. Marinas up here don't allow four stroke
self maintenance in their yards and certainly not at the slips.

Two strokes have been around for a long time, you know their reliable
(I'd get a Merc over the Yamaha any day),

Their both pigs.

Buy ETEC. :)

On Thu, 14 Jun 2007 12:30:42 -0400, Gene Kearns
wrote:

Seems like a deal until you figure back in the cost of the oil.

I know - NYOB seems to have a problem with this concept too. In terms
of ETEC only:

@ $26 a gallon for XD-100, it would seem to be expensive.

Over the summer of average use - say around 100/125 hours, you won't
even use a gallon. How many oil changes do you go through on a four
stroke every 100/125 hours?

On Thu, 14 Jun 2007 15:23:50 -0400, trainfan1
wrote:

Nothing really wrong with Yamaha except for where they're built & where
the $$ end up...

4 strokes are still new,

?

http://hometown.aol.com/homelite55/

Old technology, to some.

Ancient. Old is acceptable. :)

Wow - I haven't seen one of those on a boat in years. I know a
collector who has several of the Homelite's in his basement and both
still run.

"Gene Kearns" wrote in message
...
On Wed, 13 Jun 2007 17:40:11 -0400, D-unit penned the following well
considered thoughts to the readers of rec.boats:


"HK" wrote in message
...

I know someone considering the purchase of a 21' Parker center console,
the model with the 21-degree transom deadrise. The boat itself weighs
2750 pounds. Great open fishing boat.

Parker recommends three Yamaha engines in its four stroke line: 150 hp,
200 hp and 225 hp.

For a boat with the same hull but with a pilothouse cabin that brings
the hull weight to 3250 pounds, the Yamaha performance page indicates a
top speed of 39.3 mph with the 150 hp engine running 5600 rpm and
burning 17.5 gph. At a cruise speed of 25.6 mph at 4000 rpm, the rig
burns 7.8 gph.

I'm recommending the 150 hp engine for the 21-foot center console. I'm
guessing a top end of 42-43 mph with a fuel burn of 15-16 gph, and a
4000 rpm cruise of of 27-28 mph, burning 6.5 to 7 gph.

I don't see any need to step up to a 200 hp V6 on this boat. The days
you can comfortably run more than 25 mph in a 21' boat are rare on
Chesapeake Bay. The 150 is about $4000 less than the 200.

Any comment on the extrapolations?



Very suprising there's that much co$t difference between the 150 and the
200.

Big difference for the 4-stoke vs 2-stroke! The 150HP engine is a 4
cyl inline and the 200HP is a 6 cyl V.....

--

Most definitely,

The only difference in the old 2-stroke150/200's is carberation.....
methinks.

My old 84 yamaha 150's were so damn reliable and ran like tops. That was
the first
year they made 6-cylinder 2 strokes and they got it right except for one
thing:

Corrosion control.



db

On Thu, 14 Jun 2007 21:27:20 -0400, wrote:

On Thu, 14 Jun 2007 15:23:50 -0400, trainfan1
wrote:

4 strokes are still new,

So are the "improved" 2 strokes. I am not going to bash E-tec, the
charter captains love them but don't confuse them with your daddy's
trusty old Johnson. This is also a very high tech, computer controlled
engine that you are not fixing out on the lake with a fishing hook and
a match book cover.

Got that right. :)

I get a call from the guy who bought my Contender every once in a
while - he refers major rod repairs and builds to me.

He loves the ETECs - sorry he didn't change over when they first came
out.

If you want old tech you can still find loop charged "classic" two
strokes but they are the same old smoky gas guzzling engines that are
pretty simple under the cover. Sitll a great choice for a ski boat or
someone that likes to go fast and doesn't use the boat a lot tho..

Know a guy who has an old Hydrostream with a Merc tower on it. Kept
the boat and the engine in top shape - that thing screams.

Sucks gas like crazy though.

The best engine really depends on how you plan to use it.

Exatomundo.

Short Wave Sportfishing wrote:

Four stroke technology is inferior to two stroke technology. I have
always been a proponent of two stroke technology - in particular with
diesel engines which dollar for dollar are more efficient that four
stroke diesels.

I'm for the six-stroke...

http://www.damninteresting.com/?p=467

On Thu, 14 Jun 2007 19:48:55 -0700, -rick- wrote:

Short Wave Sportfishing wrote:

Four stroke technology is inferior to two stroke technology. I have
always been a proponent of two stroke technology - in particular with
diesel engines which dollar for dollar are more efficient that four
stroke diesels.

I'm for the six-stroke...

http://www.damninteresting.com/?p=467


Cool - although I fail to see the advantage.

On Fri, 15 Jun 2007 12:08:15 -0400, Gene Kearns
wrote:

On Fri, 15 Jun 2007 10:07:19 GMT, Short Wave Sportfishing penned the
following well considered thoughts to the readers of rec.boats:

On Thu, 14 Jun 2007 19:48:55 -0700, -rick- wrote:

Short Wave Sportfishing wrote:

Four stroke technology is inferior to two stroke technology. I have
always been a proponent of two stroke technology - in particular with
diesel engines which dollar for dollar are more efficient that four
stroke diesels.

I'm for the six-stroke...

http://www.damninteresting.com/?p=467

Cool - although I fail to see the advantage.

If I interpret correctly.....

It is using water to extract the wasted heat energy that the cooling
system would throw away.... it isn't really water injection to enhance
fuel burning efficiency, like on an aircraft. It is really a
combination gasoline/steam engine.

I see issues with shock cooling and corrosion.

Cool, nevertheless....

I understand the concept - I'm just having trouble understanding how
this becomes more efficient than a four stroke.

You still have to carry the water which is heavy and I imagine it uses
a fair amount of water to create enough oommph to move the piston on
the fifth stroke.

Interesting none the less.