inthedirtagain
Petty Officer 1st Class
- Joined
- Aug 10, 2011
- Messages
- 321
Picked up a 1983 16ft Larson All-American with a 1986 Merc 90 in early April. I've only had it out a few times, but speed seems a little slower than I would have thought for this size of boat. I've gone through the OB and its in solid shape with a good tune (120psi x 6) and recent L&S. The current 3-blade alum prop does not have any indications of size or pitch, but also is in good shape, as well. I have not pulled it off the lower unit to check for indication of size on the inside of the hub. The boat has a smooth hull with no obvious damage or hook to the transom, and the Merc is positioned so that the cav plate is right at or just under the lowest point on the transom. At WOT, I'm pulling a GPS-verified 34mph @ 4700rpm. My manual states that WOT rpm range is 4500-5000. The boat gets up on plane very quickly (about 2sec), so I'm tempted to believe that I'm under-prop'd. Manually adjusting the tilt (4th hole out) has made the most improvement with no porpoising, but not by a whole bunch (up from 32mph). Based upon this information, would you expect more out of it or am I getting the most out of the current setup? The normal load is 2 adults and 3 or 4 young kids (not beastly teenagers!). Thanks for your help.