need motor advice 1972 merc 402 40hp

ekern68

Cadet
Joined
Aug 28, 2010
Messages
17
I have rebuilt carb, put on new prop (which is identical MW prop that got chewed up 10 1/4x14) but am still running 1000 rpm lower than last year. nothing on boat has changed....same weight same water. running at 4360 rpm WOT -21mph. last year 5380 WOT. when throttle lever is wide open carb butterfly is too. where else can i look for my rpm loss cause leaving 1000rpm on the table is killing me.......thanks
 
Top