I have a 14 ft. Carolina Skiff that does everything right...except...get up
"on to plane "quickly.

I recently traded in her older 25 hp Johnson, equipped with a Stainless
steel prop, for a newer 25 hp Mercury. The Mercury came with, obviously, a
different plain aluminum prop. I have not discarded the idea that the prop
may be the answer to my puzzle...

Previously, with the older Johnson, the boat would plane out in a very short
time. I run her in West Galveston (TX)bay flats, and that means running,
most of the time, in 9 inches or so of water. With the older engine, I had
NO problem getting her up and running in very shallow water.

The new motor (25 hp mercury) doesn't get her up as fast last as the older
engine. It is entirely possible that the pitch of the "standard" prop is not
sufficient to give me a "hole shot" that the older one did.

I will probably bring the new prop in for adjustment.

I did, however, have the idea that I could simply build a few L shaped hull
extensions that would act as permanent trim tabs, and that might solve the
"getting up" problem permanently, and even add a little speed. The
extensions might eliminate re-working the prop.

Any thoughts or comments from this group would be appreciated.

RichG

On Mon, 22 Sep 2003 01:21:43 GMT, "richg99"
wrote:

I have a 14 ft. Carolina Skiff that does everything right...except...get up
"on to plane "quickly.

I recently traded in her older 25 hp Johnson, equipped with a Stainless
steel prop, for a newer 25 hp Mercury. ///
Previously, with the older Johnson, the boat would plane out in a very short
time. //
The new motor (25 hp mercury) doesn't get her up as fast last as the older
engine. It is entirely possible that the pitch of the "standard" prop is not
sufficient to give me a "hole shot" that the older one did.///
RichG


Let's raise the issue up from a level of "entirely possible"
by reading both the old and new prop data, and sharing the numbers
with us.

It is usually cast into the hub area of the prop.
If no numbers show up, The diameter is easy to measure,
the pitch not so easy, but reading the angle of a blade at the same
point on both props would give a clue, even if no numbers are to be
found.

Either too high or too low a pitch can make for slow lift onto the
plane.

Brian Whatcott Altus OK

On Mon, 22 Sep 2003 01:21:43 GMT, "richg99"
wrote:

I have a 14 ft. Carolina Skiff that does everything right...except...get up
"on to plane "quickly.

I recently traded in her older 25 hp Johnson, equipped with a Stainless
steel prop, for a newer 25 hp Mercury. The Mercury came with, obviously, a
different plain aluminum prop. I have not discarded the idea that the prop
may be the answer to my puzzle...

Previously, with the older Johnson, the boat would plane out in a very short
time. I run her in West Galveston (TX)bay flats, and that means running,
most of the time, in 9 inches or so of water. With the older engine, I had
NO problem getting her up and running in very shallow water.

The new motor (25 hp mercury) doesn't get her up as fast last as the older
engine. It is entirely possible that the pitch of the "standard" prop is not
sufficient to give me a "hole shot" that the older one did.

I will probably bring the new prop in for adjustment.

I did, however, have the idea that I could simply build a few L shaped hull
extensions that would act as permanent trim tabs, and that might solve the
"getting up" problem permanently, and even add a little speed. The
extensions might eliminate re-working the prop.

Any thoughts or comments from this group would be appreciated.

RichG


First, make sure that it's propped correctly. That could solve the
problem.

If you're a capable "backyard mechanic", you could add permanent tabs,
the problem will be to get enough "down angle" for lift, without
having too much angle, creating unecessary drag.

Why not try a hydrofoil? I added a Doelphin to my misbehaving I/O,
and it planes quicker and handles better. The cost is minimal.

....carry on.
noah

To email me, please remove the "FISH" from the net.

Compare your old prop and your new one first........
Some of the Carolina Skiff boats have a "hook" already built into the hull
to help them plane better with small motors. Fixed tabs at the angle needed
to plane quickly will force the bow down too much at speed, resulting in
plowing and slower top speed. Try one of the hydrofoils mounted on the
cavitation plate, or try some of the "automatic" tabs that are available.

Bill Sheffield