97 3.0L Alpha II (sea ray 170)
Engine hesitates slightly in the 1500-2k rpm range. It runs excellent above this range and below at idle. If I slowly give it gas it is sometimes bad enough that it will attempt to die. Most of the time if I gun it, it will jump right past the stumble rpm range and be fine. Boat tops out at 40mph.
Things I've done so far:
- replaced fuel filters (at carb, inside mech. fuel pump, installed water seperator)
- verified timing in base mode (base @1dg. btdc, normal idle at 12dg btdc)
- replaced plugs (previous were @.050, new plugs are at .035) color on old plugs looked ok.
- replaced cap/rotor (previous had carbon buildup on points)
- tweaked mixture screw at base idle set in gear/in water (700rpm) It is approx 1.5turns out. (is there a way to vacuum set it? couldn't find a port) Mercarb.
- elec. choke is two notches to the right; however, it stays all the way open all the time. I'm assuming its because its so hot outside. Shouldn't be a factor.
- accelerator pump linkage is in middle setting
- compression is good on all 4 cylinders.
I did notice that when I gun it the accelerator pump will spray strong. If I throttle slowly the gas runs down the inside of the carb instead of shooting a weaker stream.
Is it time to rebuild the carb or is there something else I've missed? If I rebuild the carb I want to know that its the problem without a doubt.
Thanks.
Engine hesitates slightly in the 1500-2k rpm range. It runs excellent above this range and below at idle. If I slowly give it gas it is sometimes bad enough that it will attempt to die. Most of the time if I gun it, it will jump right past the stumble rpm range and be fine. Boat tops out at 40mph.
Things I've done so far:
- replaced fuel filters (at carb, inside mech. fuel pump, installed water seperator)
- verified timing in base mode (base @1dg. btdc, normal idle at 12dg btdc)
- replaced plugs (previous were @.050, new plugs are at .035) color on old plugs looked ok.
- replaced cap/rotor (previous had carbon buildup on points)
- tweaked mixture screw at base idle set in gear/in water (700rpm) It is approx 1.5turns out. (is there a way to vacuum set it? couldn't find a port) Mercarb.
- elec. choke is two notches to the right; however, it stays all the way open all the time. I'm assuming its because its so hot outside. Shouldn't be a factor.
- accelerator pump linkage is in middle setting
- compression is good on all 4 cylinders.
I did notice that when I gun it the accelerator pump will spray strong. If I throttle slowly the gas runs down the inside of the carb instead of shooting a weaker stream.
Is it time to rebuild the carb or is there something else I've missed? If I rebuild the carb I want to know that its the problem without a doubt.
Thanks.
