Some questions re: 222 Sandpiper setup

[Anonymous]

Hi I'm new to this site and hope to get some insight on a few issues.  I got a 1988 222 Sandpiper last summer, powered by a 1988 225 Johnson with a 15/17 prop.  After having the engine checked out and worked on, a mechanic I have used on OMC products successfully for a long time pronounced the motor sound. The hull is clean, but not a mirror slick finish.  However, I could get only about 4600 rpm at WOT producing 32 mph, using 22 gph; he recommended less pitch.  With a 15/15 and medium load I could get 5600-5700 producing 36.5 mph (gps) WOT, consuming 17 gph.  My understanding is I should get speeds in the 45-50 range, so I suspect the motor's not producing as it should or is not set up on the boat properly. The centerline of the prop hub is 8.5 inches below the bottom of vee at the transom. I could lower it as much as 1.5 inches, or raise it.  Is my max speed low? If so, does the motor position seem off? Anybody running this same combination? Any help appreciated. Thanks, Greg

[GoneFission]

It does seem like a 17 would be about right for your boat...  How about a photo of the lower unit on the motor and the bottom of the boat?  Most likely you do not need to go down - maybe up...  Normally, the bottom of the cavitation plate should be aligned with the bottom of the hull with the engine in the trim down position.  

Is your top speed with the motor trimmed down, or up just shy of cavitating?  You will get best speed with the motor trimmed up just short of the prop beginning to cavitate or suck air.   :)

Hope this helps - good luck and welcome to the site!