prop and motor heigth

[t_brown1986]

I have a 1984 laeser bass boat.. with 1984 evinrude 115. It cam with 22 pitch stainless steel prop... It had terrible out of hole.. seems like it sets there for two mins before it moves lol.. my top end is great around 55... so im asking should i change prop?? and to what?
Also where should my motor be setting when down when boat is on trailer??

 

[ShaneCarroll]

Re: prop and motor heigth

You should get a lower pitch prop. I have come to find, the lower pitch props give you better hole shot, while higher pitch props give you better top end.

 

[Dhadley]

Re: prop and motor heigth

Maybe but lets not jump to conclusions. Let's verify the motor is running correctly. Then we'll need to know the top rpm that it's capable of now. Then where is the av plate inrelation to the bottom of the hull. We'll asume the boat is a pad bottom boat and ha sa stepped transom.

 

[t_brown1986]

Re: prop and motor heigth

i think last weekend WOT rpm was about 4000. it runs perfect!! And whith boat on trailer bottom is about 6-12 inches below boat.... has a bad problem to when i slow from a wide open throttle it will flood boat?? like over transom.... NORMAL for a bass boat?? I mean it does set low..

 

[Randybeall]

Re: prop and motor heigth

Your rpm number is quiet low for that engine. I would suspect more than one issue at hand. Dhadley was asking where is the anti-ventilation plate is in relation to the bottom of the boat. While it is on the trailer lower the engine to normal running position. Draw a straight line from the keel of the boat out to the lower unit. I like to use a yardstick and lay it on the bottom of the hull. You should find the Anti-ventilation (AV) plate pretty close, maybe a little above this point. If it is below, raise the engine on its mounting. Check this out and post your results please.

 

[t_brown1986]

Re: prop and motor heigth

ok mine is pretty close to even....

 

[steelespike]

Re: prop and motor heigth

I think your tach may be off.You need to be sure of the reading.I don't think you can make 55 at 4,000 rpm.
What is the indicated idle rpm?Is the speed by gps?
You may need to verify your tach.Your hole shot will stink with the 22.
The rpm may be low as well but 4,000 seems too low.

 

[t_brown1986]

Re: prop and motor heigth

idle rpm is around 700.. speed was by gps... and yeah went by prop shop today and guy told me hole shot was gonna blow that prop was for top speed.. he said my wot on good tilt should be 5200 to 5500...

 

[Dhadley]

Re: prop and motor heigth

If your AV plate is even with the pad the motor is too low. Way to low. And you'll be looking for a top rpm of about 5800. That prop may or may not have a bad holeshot, depends on what brand and style it is.

Get the tach verified and then work on set up. Don't buy a prop yet, lets get the set up right first.

 

[t_brown1986]

Re: prop and motor heigth

Ok my boat has a botttom "PAD" where your drain plug and live well pump inlet is.. then it steps up about 6-8 inches and has another bend.. this is what the spot where jack plate would go is even to. took prop to prop shop he said it is for speed only hole shot would blow.. and it does...

 

[Dhadley]

Re: prop and motor heigth

OK, so it is a pad bottom boat with a stepped transom. Good info. Now, if the AV plate is even with the pad the motor is way low. Let's see if we can get the numbers off the prop or a name so we know what we're working with. The only "speed" prop that has a poor holeshot is something like Merc chopper or cleaver with no barrel. A picture of the prop would be a big help.

That hull design was intended to have a jackplate. You may not be able to get the motor high enough without one.

 

[t_brown1986]

Re: prop and motor heigth

im at work today but ill get pics and prop specs up tomorrow...

 

[t_brown1986]

Re: prop and motor heigth

I do know its a 22p prop.. stainless steele.//now i am calling that flat part above the pro where the jack plate goes.. am I wrong??? Im not sure lol.. and is it good to have the type floor you say I have???

 

[Dhadley]

Re: prop and motor heigth

The theory behind the stepped transom is that you can run the engine higher. That means more efficiency from less gearcase drag. It should make it easier to get the boat up on the pad.

 

[t_brown1986]

Re: prop and motor heigth

so where should my motor be setting?? imma take it out tomorrow and play with it all.. cause it pulls hard to right.. so gonna remove my trim tab and see what happens..

 

[steelespike]

Re: prop and motor heigth

Trim Tab? do you mean the little fin under the antivent (cavitation) plate?
rear of tab needs to be turned to the right.
If your mean a fin or foil that has been added by all means remove it until the boat is all set up then leave it off.
There isn't an exact motor height.It needs to be as high as possible without creating venting(cavitation) problems.Be sure it pumps water.
A prop like a stainless or Turning Point Hustler will help reach a maximum height.

 

[t_brown1986]

Re: prop and motor heigth

the little fin is already to the right a few inches... and no i have no other fins. im gonna head to the river then ill get pics up..

 

[t_brown1986]

Re: prop and motor heigth

ok speed still not working.. but with two people in boat and fishing gear and 12 gallons of gas.. im turning 5k at wot on the best trim spot i can find... and im gonna have to change to a better hole shot prop plus be able to get some speed.. any ideas on what prop i want?? Im thinking 19-20 pitch...

 

[steelespike]

Re: prop and motor heigth

At 200 rpm per inch it seems a 18 should put you at 5,800.and give you a great hole shot. Want to go conservative a 19 or 20.

 

[Dhadley]

Re: prop and motor heigth

Your set up is way off. Don't change props until you max out what you have............