Originally Posted by SAADA
I have on my Bavaria 39 with saildrive
an alluminum 2 blades propeler. Same body as an opinion about Autoprop 3 blades
Previous owner put an autoprop on our boat - it caused us to have a strut failure. You can't just stick any prop on your shaft. Your boat is engineered for a particular prop. I would be especially cautious about this on your boat in light of the fact that you have a saildrive and your existing prop is alluminum (ie light weight - btw, are you it's alluminum?? that doesn't sound right). In any event, I assume that prop weight would be a big issue with a saildrive as you don't really have anything holding it up. Here's the long version of what we learned from our own prop/strut failure:
There was an autoprop on our boat when we bought it - we didn't think twice about it. A few months after purchase
, we were motoring down the ICW
wide open when we heard a terrifying screech, bang, boom. My husband dove the prop and found that the strut was sheered in half and one of the prop blades was missing. After haulout we dissassmbled the running gear
and took it to Caliber (our boat maker). They could not say for sure whether the prop blade broke first or the strut. (FYI, we did contact Autoprop and they told us "too bad - so sad" so if you think that you will get service
after the sale
with them - forget about it.) Caliber told us that the autoprop is way too heavy for the strut/shaft design and it quite possibly could have caused the strut to stress fracture. Further, McCreary told us that they caution Caliber owners about switching props, and particularly not to use autoprop on their boats (b/c of the weight issue). If you do switch props, contact the manufacturer and find out what props are compatible. Obviously, clearance can be an issue. If you have a folding prop, need to make sure that the rudder
has adaquate clearance. McCreary told us that he knew of a boat yard that cut a notch out of a rudder
in order to give clearance for a max prop (instead of shortening the shaft). Also, you have to consider your engine
and make sure that the pitch
is correct so that you can reach max rpms. Bottom line, from a person that has been burned by having the wrong prop installed, I would caution you to get advice from other owners and the manufacturer.
Best of luck!