stevea661
New Member
- Oct 2, 2008
- 260
- Boat Info
- 268 sundancer, humminbird 797c fish finder / chart plotter /gps combo, lowrance lms 400 with np-60 f
- Engines
- OMC Cobra 1.41 final drive ratio. 5.7 rebuilt to 300 hp 11/ 08. Hustler 15. x 15 prop. reman quadraj
Finally splashed the boat this weekend and the only problem I had was with the top speed to rpm ratio. The top speed was 30 mph on the gps, rpm was about 3400, the tac is a new replacement telleflex, the prop is 15.8" x 15 pitch, the water was pretty flat with a slight wind chop. The engine is a fresh rebuild with fresh water cooling through the manifolds. water temp was about 72, engine temp never got over 180. I'm aware that if I drop the pitch an inch I should gain 200 rpm. I am using the recomended prop for the boat according to the omc manual. I'm like 1000 rpm off. Here is what I am thinking. The tac is off, There is a differance running at altitude, I was running at about 2500' and the boat is set up for sealevel, timing could be off a little, but would that drop 1000 rpm, carb is wrong for the boat, I got this boat in non running condition, the engine is new but I reused the carb. something with the ignition system. Can anyone point me in a direction to start looking. Thanks Steve