props for twin 4 cyl volvo with xs out drives

[catfish420]

just got out of my 1985 sepeter with 1996 225 ocean pro
and into 1973 23 cc twin volvos 4 cly, sx out drives, have 19 inc alum props that turn way higher than the 4600 max on these motors was thinking at least 21 ss props ???????????

[Fr. Frank]

How much higher is "way higher"?

[catfish420]

backed off around 5300 and still had some to go the props look like reg outboard props that are on it now....

[Fr. Frank]

backed off around 5300 and still had some to go the props look like reg outboard props that are on it now....

With the same general prop geometry, 1" pitch change equals a net change of about 200 rpms. If 19" props are getting you 5300, and you need to drop 700 rpms, then you need to go to 23" pitch props.