Help in Choosing a prop to solve a problem

TAG

Cadet
Joined
Jan 26, 2009
Messages
7
Hello,
I have a 1999 aluminium Starcraft 19 1/2 ft Fishmaster powered by a 150 hp Merc. Optimax engine. This boat has a 50 gal gas tank that seems to be located in the center to stern of the boat. It also has a 9.9 kicker mounted on the stern. My point being the the boat is stern heavy. The prop is a Laser II 3 blade 14 1/2 X 19 SS. RPM's are in the 5200 - 5500 range and the speed is 34 - 37 mph. There are two problems I would like to correct. It is slow to plane and after being on plane when cutting back the throttle the stern settles back into the water too quickly. When I bought the boat there was a stingray fin on the motor. I took it off and added smart tabs. There was some improvement but not enough to make it satisfactory. It has been suggested that changing to a 4 blade 14 1/2 X 18 or 17 should be correct the problem. Any opinions or suggestions would be greatly appreciated.

Also, if I do change props should I buy stainless or aluminium?

Thanks
TAG
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: Help in Choosing a prop to solve a problem

Tag, There are props designated as "Stern lifters". I recommend reposting this in the Props Forum.

I am pretty surprized that you have bad performance with that setup. 150HP should be pretty close to max HP for that model, and a 19" pitch prop is pretty standard. You might take a compression check to make sure the motor is producing the power you expect. Check the color of the spark plugs as well. They should all be light - dark brown. White, green or black is an indication of a problem.
 

TAG

Cadet
Joined
Jan 26, 2009
Messages
7
Re: Help in Choosing a prop to solve a problem

Chris

Thanks for the quick response. I did post under props and had one reply that needed more info. The plugs are good and compression checks out fine. Max rating for the boat is 175 hp. I've never heard of stern lifting props. I'm just tired of this boat wanting to squat in the water.

Thanks

Tag
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Help in Choosing a prop to solve a problem

While you may have Smart Tabs, you may not have them adjusted correctly or you may have the wrong actuators. Call Nauticus and explain the situation. They are great people to deal with and those tabs should really help provided they are the proper size and adjusted correctly.
 
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