Having had a similar dilemma regarding placing a 4 blade prop and cowl onto this kit i decided to seek advice from OS as I am installing a 91 4 stroke engine into this model. I wrote a email to the support department at OS and had this reply
Hello Tony,
We have no experience using a four-bladed prop on this discontinued OS engine
and cannot offer any recommendations. In truth we do not test or recommend any
props beyond the standard two bladed prop. When someone asks about a
three-bladed prop we tell them to drop down one inch in diameter or one inch in
pitch from what is recommended in the engine's manual. We would not hazard a
guess on a four-bladed unit.
Art
Product Support
not much help so am stuck on getting a decent 4 blade prop set up at present any ideas on this. The Biela 4 blader is the one to go for just wonder what size