5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in message . net...
5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

Close Neal. Because of the taper fit, that won't work.

Care to elaborate on your answer?

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in message
. net...
5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN


"Bart Senior" wrote in message . net...

Close Neal. Because of the taper fit, that won't work.

Care to elaborate on your answer?

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in message
. net...
5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

Putting a LH prop on a RH setup engine would require running in reverse.
This will work on some engines/trannies, others will be destroyed by
constant running in reverse, and many will have a different gear ratio.

In any case, I think it would be noticeable on any modern setup.


Capt. Neal® wrote:
If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN


"Bart Senior" wrote in message . net...

Close Neal. Because of the taper fit, that won't work.

Care to elaborate on your answer?

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in message
. cv.net...

5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

5 points to Neal.

Inboard diesel powered boats commonly have different
gearing in reverse.

Incorrectly installing a RH or LH pitched prop when
the opposite was called for could cause a boat to
run at slower than expected speeds, albeit it would
move forward in the reverse position and vice versa.

Neal immediately grasped that the gear ratio might be
wrong and this could be explained by the boat running
in reverse, and at a lower gear ratio.



Capt. Neal® wrote
If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in

5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

(N1EE) wrote in message . com...
5 points to Neal.

Inboard diesel powered boats commonly have different
gearing in reverse.

Incorrectly installing a RH or LH pitched prop when
the opposite was called for could cause a boat to
run at slower than expected speeds, albeit it would
move forward in the reverse position and vice versa.

Neal immediately grasped that the gear ratio might be
wrong and this could be explained by the boat running
in reverse, and at a lower gear ratio.


Kinda lame question then. Who the *%*$ is not going to know the a
diffrent hand prop was installed. You either switch the tranny end of
the cable or like Neal said your gear selector is going to be
backwards!

Joe





Capt. Neal® wrote
If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in

5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

(N1EE) wrote in message . com...
5 points to Neal.

Inboard diesel powered boats commonly have different
gearing in reverse.

Incorrectly installing a RH or LH pitched prop when
the opposite was called for could cause a boat to
run at slower than expected speeds, albeit it would
move forward in the reverse position and vice versa.

Neal immediately grasped that the gear ratio might be
wrong and this could be explained by the boat running
in reverse, and at a lower gear ratio.


And you said identical. Identical is not a diffrent rotating prop.
To much rum Bart? WTF.... you usually do much better than this.
Sheeeeeze

Joe




Capt. Neal® wrote
If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN

"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in

5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

I'll take some of those points - It was me, not Neal, that pointed out
that the gearing could well be different in reverse. I also pointed out
that it would be easily noticeable.

Curiously, his first answer, that the prop was mounted backwards, may
have been a better answer. That doesn't change the handedness, but if
the blade is not symmetrical it will affect the efficiency.



N1EE wrote:
5 points to Neal.

Inboard diesel powered boats commonly have different
gearing in reverse.

Incorrectly installing a RH or LH pitched prop when
the opposite was called for could cause a boat to
run at slower than expected speeds, albeit it would
move forward in the reverse position and vice versa.

Neal immediately grasped that the gear ratio might be
wrong and this could be explained by the boat running
in reverse, and at a lower gear ratio.



Capt. Neal® wrote

If the shaft has a taper there is no way to put it on
backwards so, perhaps, they shipped a LH prop instead
of a RH prop or vice versa? Diameter and pitch could
be identical but it would be so slow if turning
direction were wrong.

CN


"Capt. Neal®" wrote

Remove it, turn it around, put it back on.

CN

"Bart Senior" wrote in


5 points (Impress me with your genius)

You just bought a new boat and notice the prop is old and brittle.

You replace it with an identical prop. After motoring around for a
while you find the top speed of the boat is much lower, estimated to
be 2.5-3 knots and the prop seems to be slipping.

What is the most likely cause, explaination, and cure?

You replaced it with one that was identical. Try
replacing it with one that isn't old and brittle.
S.

"Bart Senior" wrote in
message
. net...
: 5 points (Impress me with your genius)
:
: You just bought a new boat and notice the prop
is old and brittle.
:
: You replace it with an identical prop. After
motoring around for a
: while you find the top speed of the boat is much
lower, estimated to
: be 2.5-3 knots and the prop seems to be
slipping.
:
: What is the most likely cause, explaination, and
cure?
:
: