Hello,<br />I have a '67 Evinrude Big Twin (Mod# 40703E SER# E01637) with little power at full throttle. I rebuilt the carb w/ a kit, replaced the exhaust tube and gaskets, new fuel lines and hoses, new head gasket and water pump, new points, condensors and plugs...not much left to fix! After setting the carb. the motor starts like a dream, and runs well, but it does not seem to have as much power as I would expect. I'm trying to push a 16' fiberglass dory...so I don't think I'm overburdening it. The CG plate recomends a 40 at the max for this boat. I've tried swapping props to one with less pitch, but all I do is go slower and the RPMs stay essently the same (approx. 1700-2000 at full throttle). I can really rev it up when in neutral, so the problem seems to be when the engine is turning the prop and pushing the boat. The butterfly is wide open, so I don't think it's starving for fuel or air. I do not have a compression gauge, but I did try the thumb-over-the-spark-plug-hole trick and it seems to be strong in both cylinders....I really don't know where to go next. One last note, the carb. DOES have a high speed adjust needle, unlike the plug that the Evinrude service manual shows. Thanks in advance.
