prop sizes for twin

[randy neville]

Have a 1980 233cc with twin 470 mercs does anyone out ther have the same and know what the factory set up was . The ones are different on each outdrive  but the RPM's are not in the correct range for either but it goes fast ( 50 mph )

[David]

What are you running now and what rpm are you at wide open throttle with drives trimmed?

[randy neville]

dont know nothing legible on props but engines only turn up to 3500 port and 3800 starboard port is stuck and will have to be cut off I just want to start off at the factory settings

[David]

First find someone who will allow you to try and exchange props. I'd probably start with 14 1/4" x 19 stainless and work from there. 50 mph sound pretty fast for 3500 rpm. Have you checked tachs for accuracy?