3 blade Propeller

[c34sailor!]

I have  1988 34C and want to remove the 2 blade prop and put a 3 blade prop on. Can anyone tell me what the shaft size is and what pitch should be looking for? PS: I want to look for a used one!

Thanks Mark 657

[patrice]

Hi,

Mine is a 3 blades prop.
15 RH 10.  shaft is 1''.

[Kevin Henderson]

I have a 3 blade and the shaft is 1".  As for pitch... I'm uncertain. 

[Stu Jackson]

15 x 10, fixed three blade,  1 inch shaft

[Clay Greene]

I have a used 3-blade Michigan Sailor prop in case you are interested.  I'd have to check the measurements but it was what came with the boat.  E-mail me at greenesail@sbcglobal.net if you are interested. 

[Ron Hill]

Mark : As all have said the shaft is 1" . 
As for the pitch of a 3 bladed 15" diameter Sailor prop it is 9" when it is delivered, and most have repitched to 10" for a 3 bladed Sailor prop from Catalina. 

For a Michigan Wheel 3 bladed prop all bets are off, on what the pitch should be!!??

You might like to see my latest article in the May issue of Mainsheet Tech Notes.

A few thoughts

[Marc G]

I am a new owner of a 1987 Catalina 34 and new member here.  My boat has and Autoprop that is vibrating, and my max rpm at WOT is 2000 rpm.  I think this is rpm is too low and the engine is working too hard.

I am looking for a replacement prop, but I am on a budget after just paying for the boat. Can anyone recommend a replacement prop?
I would prefer a used one to keep my cost down.

Thanks,
Marc

[Jim Hardesty]

I'm no expert on Autoprop, I do belive they have a good reputation.  I would read the manual or call Autoprop for advice.  Could be the only thing you need is a dive & clean.  FWIW. I would not run the boat with that kind of vibration.  Could prematurely wear a number of things.  Did you or your surveyer note that presale, or is this a recent event?
Wish you luck with your new Catalina 34, when you get the bugs worked out you will find out what a great boat it is.
Jim

[n624ma]

Marc,
You are absolutely Correct about the RPM being too low, But I would check the Tachometer for accuracy.
I just replaced my prop and got a Sailor 3 blade 15x10x1 from the Catalina factory in Florida (not Catalina Direct) for $365.00.
You might give them a call 727-544-6681.

My boat is Groton so if I can give you a hand let me know. I have a photo tach if you want to check your tachometer readings.

Good luck with a great boat.

[Ron Hill]

Marc & Guys : You need to read my article in this past (May 2013) Mainsheet Tech note section issue on "Prop size, RPM and Boat Speed".

Of interest I see that Catalina factory is finally selling a 3 bladed prop with a greater than 9" pitch!!  maybe my article did some good!?!

A few thoughts

[Solstice]

I am a new owner of a 1987 Catalina 34 and new member here.  My boat has and Autoprop that is vibrating, and my max rpm at WOT is 2000 rpm.  I think this is rpm is too low and the engine is working too hard.

I am looking for a replacement prop, but I am on a budget after just paying for the boat. Can anyone recommend a replacement prop?
I would prefer a used one to keep my cost down.

Thanks,
Marc

Hi Marc,
I had an Autoprop on my 320 for 12 years and it is a great prop (and very expensive), so before you swap it out there are a couple of things that are unique to this prop and are worth checking. Make sure the blades are clean as previously mentioned. One blade will always hang down while at rest, and if you haven't used the boat in a while, it tends to get growth and will definitely cause vibration. Not sure what the WOT is for your engine, but you should be able to get within a couple hundred RPM's. Although pitch does not come into play since the prop is self pitching, blade size does. Can you find out if the PO was able to get to WOT?
The other common item to check is that the bearings for each blade are not loose. These bearings need to be serviced/replaced every 5-6 years or so. This is the only maintenance required, although some models have a grease nipple that needs an annual regrease. You can check with Steve Armitage at AB marine--he is the US Distributor for Autoprop and should have pertinent info recorded for your specific boat.
I know there is prop religion out there, but if an AP would fit on my current boat I would put one back on without hesitation! Good luck and let me know if you have additional questions...and congrats on your new boat!!

[wconnell]

I am in need of the stndard two blade prop for my 1989MKI.  If you still have the one yo took off would be interested in buying it.  My EMail address is wconnell@aol.com
Thanks.  William Connell

[Indian Falls]

Ron,

I just searched the knowledge base for "Prop size, RPM and Boat Speed" nothing...  search for prop size only: 1 hit from November 99,  I'm not sure how to find stuff that you guys suggest is so easy to find.  Is the Knowledge base the same thing as "the Index" or am I not finding the Index? Without your pointing out the month and year I don't think I could find it.  If you search the knowledge base for RPM you get one hit for May 91.  If you search for prop , it's too wide a search you get about 10 propane articles.  

Maybe you could spell out the steps taken to find this in the tech notes?  I've had trouble with searching the whole time I've been on here, say about 5 years now.  What am I missing?

I just edited this post.... I'm still at it, I searched on a page that says"search tech notes index" the search results are not the articles in the tech notes they are links to forum posts.  Am I doing something wrong?

[Noah]

Ron and other folks: What is the difference between a Campbell Sallor and a Michigan Sailer (like my prop pictured)?

[Stu Jackson]

Dan,

The Knowledgebase is current as of a few years ago when former Commodore Jon Schneider passed away.  He and I developed the categories and he did the work to "make" the Excel spreadsheet.  With all the "live" links.  It hasn't been updated since.

The Tech Notes Online are current up to about 2010.  Frederick Kohlmann and Roger Blake did a magnificent job collecting the tech notes since then up to about a year ago.  We simply haven't been able to make the time to post them.

This is a volunteer organization.  As such, we're always looking for volunteers to get some of the newer material posted, since our webmaster is busy keeping the software up to date and bug free.

As far as searching, it sounds like you're doing the right things.  If you search on this Forum, it'll pick up everything written since we started this software in 2001 or so.  The Knowledgebase is just an Excel spreadsheet, so go to the second tab at the bottom and use ctrl-F.  Yes, it picks up multiples, simply because many topics fall into different "categories."  Like, are alternators electrical or engine?  We put 'em in both.

As far as searching for "Prop size, RPM and Boat Speed", two things:  1)  I don't recall something like that combined as such in my 16years of experience on this forum --- sorry it just never came up that way, always been "What prop should I use, MaxProp, Flex-o-Fold, etc.; 2)  I've found searching on smaller words or phrases works better.  Just the nature of the search engine.  You could also try to use a separate Google search as described in one of the stickys.

If there's something specific you need help with, either  post, pm or email me and I'll see what I can do to help.

Stu

Ron,

I just searched the knowledge base for "Prop size, RPM and Boat Speed" nothing...  search for prop size only: 1 hit from November 99,  I'm not sure how to find stuff that you guys suggest is so easy to find.  Is the Knowledge base the same thing as "the Index" or am I not finding the Index? Without your pointing out the month and year I don't think I could find it.  If you search the knowledge base for RPM you get one hit for May 91.  If you search for prop , it's too wide a search you get about 10 propane articles.  

Maybe you could spell out the steps taken to find this in the tech notes?  I've had trouble with searching the whole time I've been on here, say about 5 years now.  What am I missing?

I just edited this post.... I'm still at it, I searched on a page that says"search tech notes index" the search results are not the articles in the tech notes they are links to forum posts.  Am I doing something wrong?