Prop replacement???

[Gknox61]

We bought a 1978 Catalina 30 with a Yanmar YSB12 last Sept., and sailing in Georgian Bay, Ontario.
We have a 2 blade prop and have been thinking of putting a 3 blade prop on for maneuverability.
Has anyone had any experience with replacing props.

 

[Anonymous 121765]

G,

Replacing the prop is pretty easy, in or out of the water. If unsure, get a mechanic to do it. The real question is the correct diameter & pitch. Check with Yanmar & Catalina Yachts in Calif. Ask what 3 blade prop they recommend.

One thing to keep in mind is what effect this will have on your engine. I had the universal 5411 (11 HP @ full throttle). I was grossly underpowered as the old thinking back then was 2 HP per ton. Otherwise....VERY WEAK.

My properly sized prop worked fine for six months. Then I did my first long-haul, about 600 miles. This extra strain on my engine caused my seals to leak. I bought a 20 HP engine, fixed the seals, painted & sold my 11 HP for $2500.00. This was put towards my new engine. So, do your homework first so as not to create another problem for yourself.

CR

 

[GEM555]

I've got a Cat 30 with the Atomic. Was think of using a three bladed Indegio. Anyone with experience?

 

[Nahart51]

I have an Atomic 4 with the Indigo 3 blade. Love it. It really performs in reverse with no noticeable prop walk. I can back up into my tight slip like a pro. I can't think of any negatives. It's engineered for the A4, so no worries about straining the motor.

I'm not sure it's possible to hurt an A4. I've sure tried, from running hot, to sucking water into the crankcase. Can't kill it.

I also got the electronic ignition by indigo. Best upgrade I ever did. Sometimes I start with the crank just for fun.

 

[Elysium_Van_Isl]

The Campbell Sailer (yes, spelled that way) prop works very well on our boats. And it's Canadian made too! They stand by their products, and as a comparison - a friend with one on his similar era Catalina 30 pretty much motored me under the horizon with his. I have an older, large surface area, 3 blade. The CS is on my wish list.
When I made inquiries (against my Yanmar 3YM20 with 1" shaft), they said the following:

The Campbell Sailer has cupped blades and a leading edge foil which increases thrust and lowers the slip rate. To account for this, we typically come down 2-3 inches in combined diameter / pitch from other manufacturers to put an equivalent load on the engine. Overall performance will increase and your boat will maintain hull speed longer when powering into head winds and more adverse conditions.

Also, the narrow blade profile of the Campbell prop allows for reduced drag under sail, up to 35-40% less drag when compared to equivalent size props from other manufacturers.
Their suggestion for my setup was RH13x7x1, but that would obviously depend on your engine.....

Mainesail also has a great writeup on his website for lapfitting a Campbell Sailer.

Cheers,
Mike