Procraft Prop Selection

Randy,

    I have a Procraft 1780v competitor bass boat with a 1978 Johnson GT 150 running a four blade Shooter prop. I know it is a pretty heavy boat and I have also been told that the Shooter props were pretty much crap for any type of speed. The prop does get me up on plane really quick, but has nothing after that. Which prop would you suggest on this boat? Also, after installing the prop, where would you suggest the engine height be set at? I have a jackplate on the boat and a water pressure gauge. I am only getting about 52 MPH from the boat now. I think it should run much faster than that. I would still like the boat to get on plane fairly quick, but I do want more speed. Any suggestions on any type mods to the engine would be VERY helpful!  I was wondering what the basic differences are between the GT 150 and the 175 hp model. I was told it was just in the carbs. If this is true, can I install a set of 175 carbs on the 150 to boost the hp up? Can my 150 carbs be jetted to be the same as the 175 hp carbs? What else would you suggest to get more hp from my 150? I am going to need to have the 150 worked on soon because it seems to be getting a little tired. I was wondering about any hp increases I could perform on it at that time. Would different type reeds help me any in my search for more speed?  

Thanks a million,

Larry

 

Larry & Tammy, 

Unless your motor is really tired you need set up - not motor mods. Not knowing what shooter prop pitch you have, I'd say by the way you describe the decent hole shot and not much after that, that you have the motor too high. Shooter props are not that bad, we have 20' Hydros running them over 75mph. I thing yours is a leverage problem. Bury the motor and see if it will lift the hull. You will see an 8 to10 mph increase if that is the problem. If your boat has a soft bottom then you have a big problem. That would cause the same symptom. The carbs on your GT are the same as the 175 carbs so no gain whatsoever. The motor is on the edge already so don't shorten it's life by bolting on different parts. Try lowering the motor and see if it responds. You should be in the 60's if things are right. The GT150 makes good power from 5200 on up to the 5800 limiter. If you lower it and the performance picks up but rpm is 4500ish then pitch down a couple of sizes. Good Luck. 

Randy

 

 

Please submit whatever questions you have to IHRTechTalk@yahoo.com.  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Thanks,
Mark C.

 

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