prop question for evinrude xp 150

[corbin5754]

I have a evinrude xp 150 motor with a ss 19p viper @ about 5400 rpm and 45mph @wot. im wanting higher top speed which direction do i go, or what can i do to achieve that, and is it worth it. id like to reach 50+. on a 87 baja sunsport 184

 

[Dhadley]

Re: prop question for evinrude xp 150

Is the 45 mph on GPS or a speedo?

 

[steelespike]

Re: prop question for evinrude xp 150

Check your setup raise the motor to a point just before venting(cavitation) becomes a problem.
I would think with a 1200 lb boat 50+ should be easy.
Unfortunately I can't help with high performance props though others may be able to help you fine tune the prop.Your rpm is right around the rating.5,500, so prop selection is to get the most from the boat.perhaps a prop that gets the boat up out of the water better.
You should be sure the motor is in excellent tune.

 

[corbin5754]

Re: prop question for evinrude xp 150

Gps

 

[corbin5754]

Re: prop question for evinrude xp 150

I've trimmed it that's how I got 45 I was thinking about getting a 21 or 23p ss prop should gain some speed there.

 

[steelespike]

Re: prop question for evinrude xp 150

I've trimmed it that's how I got 45 I was thinking about getting a 21 or 23p ss prop should gain some speed there.

Not talking trim but raising the motor on the transom.Did you raise it to a given demension or to
the highest point possible?Increasing pitch could improve speed but a 21 will lower rpm 200 to 400.
The 23 up to 800 rpm.Will also likely slow hole shot.You shouldn'r run the motor below the wot rpm rating.Usually the closer to the max rating the better the all around performance and motor health.
Sometimes if a prop is heavily cupped the performance can be inproved by the skilled removal/modification of some of the cup.

 

[Dhadley]

Re: prop question for evinrude xp 150

You are at about 15% slip so yes, there is a lot of room for improvment.

 

[SparkieBoat]

Re: prop question for evinrude xp 150

you may consider a jack plate and a hydrofoil. get motor high as you can without venting. the longer the jack plate the more you can go up..so a 10-12" would be good.

 

[corbin5754]

Re: prop question for evinrude xp 150

ya i just trimmed the motor for my top speed i dont have a hydrofoil but i do have smart tabs. I didnt think about raising the motor from the transom ill have to look into that i dont wanna mess with a jack plate im trying to sell this boat for a bigger one im just looking for some more speed cause i know it can go faster. if i went to a 17p prop would i go slower even though id be using more rpm or faster.. when i first bought this boat it had a 23p aluminum top speed 45 i bought a 19p ss and im getting same speed im assuming a 23p aluminum and a 19p ss equal out the same.

 

[steelespike]

Re: prop question for evinrude xp 150

release the smart tabs all the way.I've seen a couple of reports where the fastest speed was
with tabs fully retracted.If you can live with the hole shot without tabs you might be surprised at the speed.

 

[SparkieBoat]

Re: prop question for evinrude xp 150

you seem stuck on changing your prop..it will not help much probably only hurt..smart tabs do cost you a few MPH at top end, but IMO they are worth it for the better hole shot and stop bow rise/porposing. when I say raise your motor I am not talking about trimming it up, I am talking about raising it straight up. you could try putting it in the bottom holes, but you can get a good manual jack plate for about the same price as a SS prop. jack plates really help you get the max out of your rig.
and a 23 alum and a 19 SS are not the same. in order to compare props you must know what your WOT RPMs and speed is. without both numbers you are just guessing. but the 19 seems to be in the right rpm range for your motor, so you do NOT need to change your prop.

 

[corbin5754]

Re: prop question for evinrude xp 150

I do see where i can lift the motor higher on the transom its at the lowest it can go now mabe 2 inches it can be lifted. What kind of gain will i see by lifting it to its max of 2 inches i have plenty of room without it venting.

 

[steelespike]

Re: prop question for evinrude xp 150

In ideal conditions 2 to 3 mph is possible.If the motor is really low 2" without venting may work really well. I have seen 2 to 3 mph and as little as a few tenths.
Many boats end up with the anti vent plate about an inch above the bottom.
Generally raising the motor will improve handling and very slightly improve hole shot
but sometimes no real change.The right prop will allow the most height without venting.

 

[reddogg]

Re: prop question for evinrude xp 150

When I got my boat the vent plate was 2" below the bottom, I raised it to 1/2" below the bottom and gained 3mph and approx 200rpm. I'd like to go higher but than I'd have to use a jack plate or drill new holes and don't want to do that. Most say that the ideal spot for the motor is to have the vent plate evan with or up to 1/2" above the bottom.

red

 

[corbin5754]

Re: prop question for evinrude xp 150

anybody know a easy way to lift the motor by yourself.

 

[reddogg]

Re: prop question for evinrude xp 150

It's easy to do. Lower your trailer all the way down. Place a few 4x4's under your motor and loosen (not remove) the bolts. Start raising the trailer and the motor will raise up. Most motors have 4 bolts, two up top that go in holes and two in the bottom that are in slots. You can take out the top ones and let the motor slide up on the bottom one's.

red

 

[corbin5754]

Re: prop question for evinrude xp 150

right on im going to try that now..

 

[corbin5754]

Re: prop question for evinrude xp 150

i got started on it i had to go to work so i only had time to raise it one bolt hole higher but im getting there, thanks for all your help.