I have a 1975 38 C&C with 15000# displacement, 6 foot draft. I put in a new 28 hp beta diesel last year. The prop is a Campbell sailer 15x8x3. I have noticed black smoke with rpms greater than 2000. This is not new. I contacted Campbell prop company and they are recommending changing prop to 14x7x3, thinking the engine is over-proped. Others have told me a 16x8x3 standard prop is recommend. Any comments or recommendations. I also notice my fuel usage a bit higher than expected. Under no load there is no smoke at any rpm. Thanks Brad
Cambell are quite correct. You are overpropped but because of the twist that they put in the their blades, their props react differently to normal props and they often have a few times to make changes before they get it close to right. I suggest that you try a sailor style propeller as made by Michigan Wheel or their DJ355 prop. These props will perform well and give you the results that you want.
Please let me know how you get on, Regards, Stanley
