342 Performance Issue

buggyjdav

342 with twin Merc 350 Horizons. Having trouble getting on plane. Did a 3 hour run in the Ocean yesterday, good conditions, 1-2 ft waves. At wide open throttle I can't get above 4000 rpm or more than 25 mph. Seems that going above 75% throttle does nothing, no more rpm nor speed. Could it be that the throttle cables need adjusted/replaced? Trim tabs working, no bottom growth. 

Black_Diamond

This a new problem?  A few things to look at: cap/rotor, spark plugs, weight on boat (passengers/fuel).  It really sounds like mine when it was over propped. 

buggyjdav

Props were the issue, had them machined

Black_Diamond

What drives are you running?  They modify the pitch or were they damaged?