Hello,
This is my first post here so I wasn?t sure where to post this. I have an 85 Larson 19? open bow with a 3.8 185 hp Mercruiser with an Alfa 1 drive 1:84:1 ratio that I just got. According to the paperwork it weighs 2235lbs without the motor, so I?m assuming around 2800lbs with the motor and full 20 gallon tank and driver. Here is my problem. It came with a 14.25 x17? aluminum prop on it. The boat will do 35 mph WOT at 4700 rpm. I put a Quicksilver SS 14.25 x 19? on it and the best it would do is 32mph at 4200 rpm WOT. The manual states 4400 to 4800 WOT. I have read everywhere on forums that I should only be loosing about 200 rpms and that this motor has enough hp to pull this prop. I tried pulling a 145lb expert skier and it was all the boat could do to get him out of the water and it doesn?t plane for a long time. Shouldn?t this boat be able to perform better than this? Even with the 17? prop it is disappointing in the hole shot and takes from dead stop to plane more than 100 feet. I had the timing and carb adjusted from a professional in the area and the motor seems to run good except for a tiny flat spot when you first hit the gas. I guess my question boils down to how can I improve the performance of this boat so it will pull a 200lb skier and not drown them in a deep water start? What prop would be the best? I have checked around and there is no ?try it and see? program for props around here. Thanks in advance.
This is my first post here so I wasn?t sure where to post this. I have an 85 Larson 19? open bow with a 3.8 185 hp Mercruiser with an Alfa 1 drive 1:84:1 ratio that I just got. According to the paperwork it weighs 2235lbs without the motor, so I?m assuming around 2800lbs with the motor and full 20 gallon tank and driver. Here is my problem. It came with a 14.25 x17? aluminum prop on it. The boat will do 35 mph WOT at 4700 rpm. I put a Quicksilver SS 14.25 x 19? on it and the best it would do is 32mph at 4200 rpm WOT. The manual states 4400 to 4800 WOT. I have read everywhere on forums that I should only be loosing about 200 rpms and that this motor has enough hp to pull this prop. I tried pulling a 145lb expert skier and it was all the boat could do to get him out of the water and it doesn?t plane for a long time. Shouldn?t this boat be able to perform better than this? Even with the 17? prop it is disappointing in the hole shot and takes from dead stop to plane more than 100 feet. I had the timing and carb adjusted from a professional in the area and the motor seems to run good except for a tiny flat spot when you first hit the gas. I guess my question boils down to how can I improve the performance of this boat so it will pull a 200lb skier and not drown them in a deep water start? What prop would be the best? I have checked around and there is no ?try it and see? program for props around here. Thanks in advance.
