C30 prop advise needed

[SailingWebGuy]

Hello!

I have a 1976 Catalina 30 with an A4. I have almost zero thrust in reverse...docking has been a bit challenging. It currently has a tiny 2 blade prop and I don't know any specifics on it.

Has anyone had a similar issue and had good results with an upgrade? What did you upgrade to?

Any info would be a huge help. Thanks!

[BELLATRIX1965]

Our boat had a fixed-pitch 2-bladed prop when we bought it, and nearly no astern thrust. Yes, docking WAS a challenge! We found later that the transmission was slipping in reverse, so check and adjust THAT first!

After much study, we purchased a Variprop feathering 3-bladed propeller.

VariProp USA - The best feathering and folding propellers in the world!

It is a robust, well-engineered German propeller, and the (very helpful) USA distributor is right in Thomaston, Maine. A wonderful piece of machinery, but EXPENSIVE! They now offer a "variprofile" prop that is similar, but quite a bit less costly. One advantage of the Variprop units is they can be adjusted for ahead and astern pitch without taking the prop apart. Adjustment can be made fairly easily by a diver with the boat in the water if necessary.

Check them out! One point if you do buy one - the custom-formed zinc "tail cones" can be purchased generically on line a lot cheaper than going back to the manufacturer. HAPPY MOTORING!

[mitiempo]

A4 engines spin a smaller prop faster - usually no reduction gear.

Here is a link to props specifically for the A4 Boat Seem Underpowered?

[CalebD]

SWG,
Bellatrix makes a good point about the reverse gear. On our A4 we have to hold the shifter all the way back in reverse for it to begin to grab and spin in reverse. Our reverse gear is reduced so you also need to use more throttle in reverse then forward for the same prop rpms.
I have not tried the Indigo prop on our boat but I have heard good things about it. If you are not racing and don't mind a little drag this 3 blade prop is designed for use with the A4: Boat Seem Underpowered?
Hope this helps.

[celenoglu]

The best prop is the one with only one blade. since it is not possible to balance it, we use the second best with two blades. Although it is easier to balance a prop as the number of blades increase, the efficiency decreases. It is up to your gear ratios not to your prop. Applying more power in reverse will help if everthing is working OK.

[mitiempo]

The best prop is theoretically one with one continuous blade, not one blade sticking out. But it doesn't exist.

A 3 blade is both more efficient and smoother than a 2 blade.
West by North Enterprises - Choosing a Propeller

[tommays]

I have a 12 x 8 2 blade on the Cal 29 and it is on the BIG side and i will be buying a 12 X 7 flex-o-fold over the winter

The A4 seems real happy with the 12 x 8 at 1400 to 1500 RPM and has pushed the boat with no problems in 30 knots BUT i want a bit more RPM

[SkywalkerII]

Does your A 4 have a reduction drive? My C&C 34 has a 2:1 reduction so she spins a 16 inch prop. My Tartan 27 is direct drive and spins a 12 inch.

I have a 16 inch two blade feathering Maxprop if you are interested.