Which is the right 3 blades prop for my
Bav 40 2001 with engine MD22L BT and drive Unit 120S-E 2.20
17 x 15 left Geoff on 40cc 2001
Is not 40 cc
Is 40 3 cabins
Does it make any difference?
No. 17*15 was fitted to many boats of around 40' and the 50hp engine. First check the prop you have - the size will be stamped on the boss but often difficult to find under years of crud. second a way to check that the size is correct is to do a run at maximum with a clean bottom and flat water. You should be able to get within 200rpm of the quoted maximum rpm for the engine.
Note that the size is only for the fixed 3 blade. Folding and feathering props are often a different size and best to check with the maker of the prop for the recommended size.
If you have the old prop available and it was correct dimension, here are instructions, template and app on how to determine size (incl. pitch) https://sites.google.com/site/thepropellerhub/simple-pitch-measuring (https://sites.google.com/site/thepropellerhub/simple-pitch-measuring)
Our three-blade folding (Volvo) prop is 18x15 on 2001 3-cabin Bavaria 40 with MD22 engine
An older thread on same topic http://bavariayacht.org/forum/index.php/topic,2289.0.html (http://bavariayacht.org/forum/index.php/topic,2289.0.html)
BR,
Tommi
s/y Anniina
Thanks to everyone for your help, always valuable