28 te prop removal

[jleonard]

she easily hit 4,200 rpm. "Scary" is an understatement!

Not for the faint at heart.
WEAR EARPLUGS esp when you do the under load test. Turbo whine is not your ear drums' best friend.
I said......

[RobS]

WEAR EARPLUGS......

Yup, a pair of orange safety headphones are stored on board all season for routine engine room checks while underway. They come in handy for rpm checks too.

[Serenity]

Rob FYI the attached is the original label on the box for the new prop including the cup size

prop specs.pdf

[Serenity]

Prop is on and ready to go. As per the gurus at B & S, this three blade prop will deliver better performance than a 4 blade. We shall see.

005.JPG

[jleonard]

A 3 blade will be more efficient and will back better than a 4 blade.
However, the "thumps" on the hull will have a different frequency (spaved farther apart) and you "may" feel a vibration.

Hopefully only the more efficient and better backing will apply!!

[RobS]

And mathematically it should be 25% cheaper to get reconditioned when you run aground in Moriches!

[Serenity]

That is why I wanted your cell

[RobS]

Well the shoaling changes season to season, will see in a couple weeks what this year has to offer...

[jleonard]

And mathematically it should be 25% cheaper to get reconditioned when you run aground in Moriches!

I like the optimism!

[Serenity]

Skegs are a wonderfull thing

[Serenity]

Prop is on and ready to go. As per the gurus at B & S, this three blade prop will deliver better performance than a 4 blade. We shall see.

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Serenity splashed this morning in 15-20 knt NW winds, just my kind of weather. The new prop was great, will have to do some further sea trials to record the results, but so far excellent. Went to back into my slip, with the wind on my nose, and the boat tracked back like I was on a rail. Didn't have to raise my voice to the bride to do this and do that. This weekend I expect to monitor rpm's and speed and top end.

[Serenity]

Took Serenity out this afternoon on Great South Bay, Long Island. I recorded the speed by GPS and paddler off of the thru hull transducer. The Tach is a Aetna digital. Tide was going out and the winds were ight out of the SW.

RPM's GPS Knts Trans
2000 8.2 7.0
2500 15.5 14.0
2800 18.6 17.0
3000 20.6 18.7
3300 23.9 21.9
3600 26.2 24.5
WOT 3665 26.5 24.6

Full fuel, 25 gallons water, me plus a couple of beverages. On another note, I find that this 3 bladed prop allows the 28 to back much easier. I will talk to B&S about hitting higher RPMs. I am happy with the prop.

WOT high idle no load 4250 & scary
2800

[RobS]

Yup, you'll need to get a good 200rpms back. Estimating an inch of pitch per 100rpms, I wonder if he can get that out of that prop. Curious what he has to say...

[Serenity]

I am curious as well. It could get expensive pulling boat, have the prop reworked, putting it back on and hoping all is good. I'll, let you know when I talk to Tommy at B&S

[RobS]

Well the "rework" should be on him, you gave him boat specs and he selected the dia, pitch, etc. Right? If he questions the accuracy of your tach I can meet you with the phototach. That is not it though, you have an Aetna, as long as its set for a 117 tooth flywheel you are right on..