original prop

Question
I am looking for the specs for the original prop for  a 1994 Wellcraft 2700 Martinique with a 7.4 Mercruiser with a Bravo II outdrive. I used to get 32 mph at 3200 rpm when new. Just replaced the engine with a new 7.4 Mercruiser as the compression was poor. Still drawing too many rpm to maintain plane. Need to have 3700 rpm to maintain plane at 32 mph. Wondering if the prop pitch is correct. Also, I now have a Stainless steel prop while the original was aluminum. Would the aluminum prop flex at plane give same speed at lower rpm? Thanks. John

Answer
Hi John...Thank you for selecting the undersigned to reply to your question.

I'm not mechanical technician but, yes, an aluminum prop will flex slightly at top end, whereas a stainless steel prop maintains its rigidity, including cupping. Sounds to me you need to drop down on the pitch not the diameter, and test a degree or two of different props.

Safe Boating
Ron