I have changed props (and even shafts) in the water on other boats, using a
snorkel and mask. However, I'm now almost 68 and can't stand the 50 deg.
water of Puget Sound. (my wet suit no longer fits, I wonder why?).

Background: I always carry a spare prop, key, nut, cotter pin, prop puller
and wrenches. Total weight ~45# (stored low in boat).

My spare prop is a 17"X 11", 3 blade, LH and the prop I launched with was
the OEM 15"X 12", 3 blade, LH. I was told by the fellow I got the spare prop
from that it gave him much better maneuverability in his Ingrid 38 with the
same engine as mine.

This week I looked over the side and saw how clear the water was (albeit
around 50 degrees). My Ingrid being double ender, I could see the prop
clearly and it's winter beard growth. I got into the inflatable with a brush
and stainless scrub pad, with the intention of just cleaning the beard and
any shell growth. I soon discovered that if I laid prone on the dingy
thwarts, I could reach the prop and even the prop shaft.

After cleaning everything I got to thinking, maybe I could do this "In the
water" from the dingy. Got out the spare and the tools, along with a bunch
of twine for tool lanyards.

The first problem was the cotter pin. I had wrapped the ends around to
prevent them from fouling or catching fish lines. Difficult to get the ends
bent back straight enough to pull out. I could only get one hand deep enough
for this task. Also my engine gear box only holds the shaft in one direction
in fwd and other direction in reverse. Should have had a helper at the
control. Finally had to go get my good vise-grips and use them to grip the
cotter pin. (Oh-Well, they're Craftsman, I can always return them if the
salt water damages them).

I was relieved to find that I had the correct wrench size (the 1 7/16" had
me puzzled but it turned out to be correct). The jam nut and main nut came
off without a problem. I opted to leave the main nut on the end of the
shaft for the puller plate to bare against and prevent the prop/puller from
sliding off the shaft before I was ready.

Next problem was mounting the plate puller. I could only leave one bolt in
the two plates while placing the bolt between the blades, then inserting the
second bolt into place. Both of these operations required both hands and by
this time I was extending my upper body over the side to a point that my
noise was touching the water.

I realize the inflatable was stable enough I could have been using my face
mask for better visibility. (next time)

I learned that my puller bolts could have been an inch longer. However I was
able to manage to get all three inserted and nuts installed. Also, I'm going
to modify the back plate with a counter bore that will hold this plate
centered over the shaft end or nut.

Once I started hand tightening the bolts, I found I could bring the back
plate up to "about" center. Once I applied wrench pressure, it didn't take
more than a snug and about a half turn and the prop was loose.

Since I had a safety line on both the prop and the puller, I removed the
remaining prop nut and then slide the mass off the shaft and into the dingy.

Installing the spare prop was pretty easy.
(in a previous post I mentioned that my spare prop was the wrong bore size.
Turned out that The Prop Shop determined that my spare was correct, 1 1/4"
and I had been going by the larges bore, which is always a bit smaller than
the shaft taper.) Anyway I verified that the keyway and bore didn't have any
burr and that the key fit correctly. I greased the bore, verified that the
key was still in the shaft keyway. Installed a safety lanyard on the prop.
Leaned over the side and slide the prop onto the shaft until I could feel it
touch the key, rotated it slightly to find the prop keyway, Bingo, it slide
on. Most of this required both hands.

Installed the nut, jam nut and cotter pin. This time I used a shorter pin
and only spread the ends enough to a few degrees (as recommended by ABYC).

Soaked all my tools in fresh water and blow dry with heat shrink gun and
sprayed with WD 40.

Next: Dock and Sea Trials.

Engine rpm at dock in Fwd and Rev just slightly higher than with OEM prop. I
can see my the prop discharge astern, I'm moving more water.

Getting out of my slip was much easier, "back & fill" much more effective.
Once away from the dock, using back & fill, I turn this 13.5 ton full keel
boat in it's own length 180 degrees with about "12 bells" (old navy term).
Of course I have to give partial credit to the 'barn door' I have for a
rudder and large prop aperture.

In open water I found I was get 5 knots/1500 rpm (3 kt improvement), 6
kts/1800 and 7.2 knts at 2100..

Since the engine only has about 150 hours on it, I didn't push it beyond
this but there really wasn't much throttle left. (I think the MD2B develops
it's full 25 hp at 2500 rpm (don't have the manual here).

Anyway, I'm happy with the extra knot or 2 since I've always been content to
motor at 5-6 knots. The largest benefit is that increased docking ability
for this boat. In backing into a slip, I found I could actually turn the
stern with the rudder, kinda like driving a fork lift. However the back &
fill is really greatest benefit.

Now I guess I better go pay the fellow for the 17" prop. He kinda let me
have it 3 years ago, on consignment, until I could try it out.

Sorry this was so long, Kinda like a Blog!!


--
My experience and opinion, FWIW
--
Steve
s/v Good Intentions

I like that part about the safety lines on the prop and puller ;-)
Now aren't you glad you didn't have to try this out in 2' chop!!

Later,

Don W.

Steve wrote:

I have changed props (and even shafts) in the water on other boats, using a
snorkel and mask. However, I'm now almost 68 and can't stand the 50 deg.
water of Puget Sound. (my wet suit no longer fits, I wonder why?).

Steve wrote:
I have changed props (and even shafts) in the water on other boats, using a
snorkel and mask. However, I'm now almost 68 and can't stand the 50 deg.
water of Puget Sound. (my wet suit no longer fits, I wonder why?).

Background: I always carry a spare prop, key, nut, cotter pin, prop puller
and wrenches. Total weight ~45# (stored low in boat).

My spare prop is a 17"X 11", 3 blade, LH and the prop I launched with was
the OEM 15"X 12", 3 blade, LH. I was told by the fellow I got the spare prop
from that it gave him much better maneuverability in his Ingrid 38 with the
same engine as mine.

This week I looked over the side and saw how clear the water was (albeit
around 50 degrees). My Ingrid being double ender, I could see the prop
clearly and it's winter beard growth. I got into the inflatable with a brush
and stainless scrub pad, with the intention of just cleaning the beard and
any shell growth. I soon discovered that if I laid prone on the dingy
thwarts, I could reach the prop and even the prop shaft.

After cleaning everything I got to thinking, maybe I could do this "In the
water" from the dingy. Got out the spare and the tools, along with a bunch
of twine for tool lanyards.

The first problem was the cotter pin. I had wrapped the ends around to
prevent them from fouling or catching fish lines. Difficult to get the ends
bent back straight enough to pull out. I could only get one hand deep enough
for this task. Also my engine gear box only holds the shaft in one direction
in fwd and other direction in reverse. Should have had a helper at the
control. Finally had to go get my good vise-grips and use them to grip the
cotter pin. (Oh-Well, they're Craftsman, I can always return them if the
salt water damages them).

I was relieved to find that I had the correct wrench size (the 1 7/16" had
me puzzled but it turned out to be correct). The jam nut and main nut came
off without a problem. I opted to leave the main nut on the end of the
shaft for the puller plate to bare against and prevent the prop/puller from
sliding off the shaft before I was ready.

Next problem was mounting the plate puller. I could only leave one bolt in
the two plates while placing the bolt between the blades, then inserting the
second bolt into place. Both of these operations required both hands and by
this time I was extending my upper body over the side to a point that my
noise was touching the water.

I realize the inflatable was stable enough I could have been using my face
mask for better visibility. (next time)

I learned that my puller bolts could have been an inch longer. However I was
able to manage to get all three inserted and nuts installed. Also, I'm going
to modify the back plate with a counter bore that will hold this plate
centered over the shaft end or nut.

Once I started hand tightening the bolts, I found I could bring the back
plate up to "about" center. Once I applied wrench pressure, it didn't take
more than a snug and about a half turn and the prop was loose.

Since I had a safety line on both the prop and the puller, I removed the
remaining prop nut and then slide the mass off the shaft and into the dingy.

Installing the spare prop was pretty easy.
(in a previous post I mentioned that my spare prop was the wrong bore size.
Turned out that The Prop Shop determined that my spare was correct, 1 1/4"
and I had been going by the larges bore, which is always a bit smaller than
the shaft taper.) Anyway I verified that the keyway and bore didn't have any
burr and that the key fit correctly. I greased the bore, verified that the
key was still in the shaft keyway. Installed a safety lanyard on the prop.
Leaned over the side and slide the prop onto the shaft until I could feel it
touch the key, rotated it slightly to find the prop keyway, Bingo, it slide
on. Most of this required both hands.

Installed the nut, jam nut and cotter pin. This time I used a shorter pin
and only spread the ends enough to a few degrees (as recommended by ABYC).

Soaked all my tools in fresh water and blow dry with heat shrink gun and
sprayed with WD 40.

Next: Dock and Sea Trials.

Engine rpm at dock in Fwd and Rev just slightly higher than with OEM prop. I
can see my the prop discharge astern, I'm moving more water.

Getting out of my slip was much easier, "back & fill" much more effective.
Once away from the dock, using back & fill, I turn this 13.5 ton full keel
boat in it's own length 180 degrees with about "12 bells" (old navy term).
Of course I have to give partial credit to the 'barn door' I have for a
rudder and large prop aperture.

In open water I found I was get 5 knots/1500 rpm (3 kt improvement), 6
kts/1800 and 7.2 knts at 2100..

Since the engine only has about 150 hours on it, I didn't push it beyond
this but there really wasn't much throttle left. (I think the MD2B develops
it's full 25 hp at 2500 rpm (don't have the manual here).

Uhh, you should be able to get to full RPM in flat water.
If you can't maybe you've overpropped the boat. After 150
hours you should be able to apply full power and find out.

Evan Gatehouse

"Evan Gatehouse" wrote in message
...

Uhh, you should be able to get to full RPM in flat water. If you can't
maybe you've overpropped the boat. After 150 hours you should be able to
apply full power and find out.

Evan Gatehouse

My OEM prop (provided with the engine, by Volvo) actually only lets me run
at about 2200 rpm.

Admittedly my bottom is a bit foul and I'm push a lot of windage. And the 7
knots is about hull speed for this boat. (judging by the quarterwave).

The next time I pull the prop, might have them take a bit off the pitch. I
want to keep this diameter though.

Steve
s/v Good Intentions