Is this the correct prop?

sceptre

Recruit
Joined
Feb 21, 2006
Messages
2
I have a alumacraft trophy 180 and a 2005 johnson 115 4 stroke. The prop is a omc 14x21 alluminum max rpm is 5800 and the loaded weight of the boat is about 3000 lbs.<br /> The reason I am asking this question is to get the rpm up I have to trim the engine pretty high, if I go into any kind of a turn the prop blows out. For any kind of a holeshot I need to trim the engine completely down. <br /> Speed is at 36.5 on the gps I dont want to loose any more speed but the handling must be improved. Any recomendations on how to improve the handling and keep my hand away from the trim switch so much?
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Is this the correct prop?

You are close on the RPM's. What is the cavitation plate height in relation to the bottom of the stern? Even, Below, above?? You may be able to raise the motor up a notch or two and gain the RPM's you need. If not or it is correct, going to a 19" pitch should get you where you need to be... Let us know..
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: Is this the correct prop?

Originally posted by sceptre:<br /> Any recomendations on how to improve the handling and keep my hand away from the trim switch so much?
:D Get used to it, thats the way they work. :D
 

Mischief Managed

Lieutenant Commander
Joined
Dec 6, 2005
Messages
1,928
Re: Is this the correct prop?

A prop with more cup and perhaps more rake should help prevent the blowout in turns. When I switched to a raked and cupped SS prop, I was shocked at how much more I could trim up and still not blow out on my old boat.
 

ob15

Chief Petty Officer
Joined
Jan 4, 2004
Messages
514
Re: Is this the correct prop?

Having to trim in a little in turns is normal for a boat that is set up pretty good.<br /><br />A SS prop with some nice cup would help a lot. You would probably have to drop to a 19" pitch though. <br /><br />What is the max rpm for this motor?
 
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