Okay here it goes have a celebrity 208 status. When I received the boat it hasn't ran in years. Long story short got her running like a top. Only problem is she has no speed. . Here is her specs:
Mercruiser alpha 1 5.7l motor
Mercruiser alpha 1 1.5 ratio leg
Prop on boat 14x19 aluminum in rough shape tested with this prop wot only 3800 rpm @ 58.9 km/h done with gps.
Changed to a 14x17 prop and now wot 4400 rpm @ 54.8 km/h with gps.
Timming of motor is 8 btdc@ 750 rpm and 28 btdc @ 3200 rpm.
Boat runs strong but only goes that 55 ish km/h which I think is kinda slow for a 5.7 motor. Oh ya the motor was new prior to me getting the boat. When I trimmed the boat with the 19 prop on it I could trim it almost to the stop without any cavitation but with the 17 prop I can only trim it a quarter then it starts to cavitat really bad. Is there anything I am missing? I know this is a big boat at almost 21 feet and 3700 lb's with fuel and passage but I feel it should do close to 80 km/h from what I have read with comparable boats. Any and all help is great fully appreciated.
Mercruiser alpha 1 5.7l motor
Mercruiser alpha 1 1.5 ratio leg
Prop on boat 14x19 aluminum in rough shape tested with this prop wot only 3800 rpm @ 58.9 km/h done with gps.
Changed to a 14x17 prop and now wot 4400 rpm @ 54.8 km/h with gps.
Timming of motor is 8 btdc@ 750 rpm and 28 btdc @ 3200 rpm.
Boat runs strong but only goes that 55 ish km/h which I think is kinda slow for a 5.7 motor. Oh ya the motor was new prior to me getting the boat. When I trimmed the boat with the 19 prop on it I could trim it almost to the stop without any cavitation but with the 17 prop I can only trim it a quarter then it starts to cavitat really bad. Is there anything I am missing? I know this is a big boat at almost 21 feet and 3700 lb's with fuel and passage but I feel it should do close to 80 km/h from what I have read with comparable boats. Any and all help is great fully appreciated.