prop problem

[WHITEBOYY32]

i have a bass tracker pro-18, it needs a prop. i was wondering which would be the best performance, a 3 blade or 4 blade with the same pitch at the same price. somebody please tell me which one would be best for my tracker cause i don't know the difference between 3 and 4 blaed props.

 

[Bayrider]

Re: prop problem

Hi Paul. The 4 blade would run a bit smoother over all but you will have to drop the pitch to stop the engine getting over worked.If the boat is performing at correct RPM at WOH with your current prop (3 blade)then you might have to drop 2" of pitch for the 4 blade.Hope this helps.

 

[WHITEBOYY32]

Re: prop problem

hey bayrider, why would the engine get overworked(and whass overworked mean) when the pitch is the same? and what would the 4 blade do to my top speed, increase it or decrease it?

 

[Bayrider]

Re: prop problem

Hi Paul.If your boat is running at correct RPM with the 3 blade and you change to 4 blade (same pitch)then recommended RPM will drop by about 200rpm therefore the engine will labour and performance will drop.If you drop the pitch on the 3 blade then RPM will increase and you will over rave the engine.The 4 blade is that little bit harder to turn through the water,that is why you need to drop the pitch.As for the top speed, it will most likely stay about the same,but the hole shot,etc should be a lot smoother.If you know the relavent details of your boat i.e prop size, weight etc. then go to WWW.mercury.com/propselector and punch in your details .It will give you a list of props that are suitable to your setup. Hope I have made a little easier to understand. Regards Raymond.

 

[Bayrider]

Re: prop problem

Sorry Paul. That should be www.mercurymarine.com/propselector

 

[Chris1956]

Re: prop problem

Paul, Can I use you post to get some prop advise myself? I have a 16 ' speedboat with a 150HP IL6. I would like a prop that lifts the bow more than the OEM 21" pitch three blade. The current prop probably has nearly the correct pitch, but is the Rapture or Stiletto (or other brand) a better choice than the OEM?

 

[bluewater19]

Re: prop problem

Try a tempest plus 21 pitch. Also the laser II is a good bow lifter. I have tried both on my boat and the tempest lifts a little more but the laser provides the best hole shot.

 

[Dhadley]

Re: prop problem

Given you are trying a 3 blade and a 4 blade with the same technology design, a 4 blade will run a higher X dimension (higher on the transom). With todays advanced 4 blade props we sometimes will not recommend one unless you use a jackplate to get the right height. <br /><br />To get the "right" prop for your rig, you start with defining the intended use. Then its a matter of dialing it in.

 

[Jdeagro]

Re: prop problem

Try this Post as it covers wide range of performance issues including prop changes.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008719