why wont it go FASTER!!!

[dazk14]

Re: why wont it go FASTER!!!

drew up a plan of what i'm thinking about doing with my dry box so i can move the battery up farther in the boat

View attachment 130359

If this is something you want to do for your boat - regardless of speed - great.

If it takes more than 15minutes to set up, you're going about this "speed" thing wrong. Simple movement weight shifts - nothing fancy.

I see 120 posts on this thread and does anyone have a clue what prop pitch he's using. What about the prop swap "talk" that occurred about a hundred posts ago?

Can't borrow a tach? The auto parts stores usually give free loaners. You can buy a knock-off "Tiny tach" for $10 on ebay that will fit on nearly any motor. The jet-skier's live on those.

Maybe I'm missing something here...

 

[all duck'd up]

Re: why wont it go FASTER!!!

If this is something you want to do for your boat - regardless of speed - great.

If it takes more than 15minutes to set up, you're going about this "speed" thing wrong. Simple movement weight shifts - nothing fancy.

I see 120 posts on this thread and does anyone have a clue what prop pitch he's using. What about the prop swap "talk" that occurred about a hundred posts ago?

Can't borrow a tach? The auto parts stores usually give free loaners. You can buy a knock-off "Tiny tach" for $10 on ebay that will fit on nearly any motor. The jet-skier's live on those.

Maybe I'm missing something here...

15 min to set up what?

as to the prop everyone figured it was a weight problem so im adjusting it

i will pull the prop tonight and post the size tomorrow

i looked on ebay and didnt see a tinytach's for less than 40 + shipping so ill have to check my local parts store for a cheaper 2 stroke tach that will fit my boat

 

[steelespike]

Re: why wont it go FASTER!!!

There are optical or lazer tachs that you put a mark on the flywheel and count the revolutions with it.
Difficult to use while underway but it can be done.Keep in mind
both it and the tinytach can be used on allmost any motor one cylinder or 16 cylinder. marine, automotive
industrial,lawnmower etc.. Sometimes it takes some math.

 

[fishrdan]

Re: why wont it go FASTER!!!

View attachment 128201

(if pic doesn't show, go back a couple pages...)

as to the prop everyone figured it was a weight problem so im adjusting it

i will pull the prop tonight and post the size tomorrow

I wouldn't rule out a prop issue as from the pic, it looks kind of hammered. Tough to tell though, it might just be paint scratched off. As said earlier, you'll need a tach (tiny tach?) to figure out the engine RPM for best prop selection...

I know this was mentioned earlier, how about asking your buddy to try his prop, if it will fit your OB?

 

[smokeonthewater]

Re: why wont it go FASTER!!!

15 min to set up what?

as to the prop everyone figured it was a weight problem so im adjusting it

i will pull the prop tonight and post the size tomorrow

i looked on ebay and didnt see a tinytach's for less than 40 + shipping so ill have to check my local parts store for a cheaper 2 stroke tach that will fit my boat

What he's telling you about 15 minutes, is: Don't set up, design, or build anything, just chuck as much weight as you can from the back to the front any way you can and try it.... THEN figure out how you want to set up your box and such to make it nice if it helps

http://www.ebay.com/itm/Inductive-T...Parts_Accessories&vxp=mtr&hash=item1c1e0fa1ef

http://www.ebay.com/itm/Hour-meter-..._Accessories_Gear&vxp=mtr&hash=item1c20007b38

 

[all duck'd up]

Re: why wont it go FASTER!!!

the prop is a 9.25 X 11

looking into getting a tach

 

[steelespike]

Re: why wont it go FASTER!!!

11" is the largest readily available prop.Is the prop in excellent condition?
Have we checked that the throttle is opening all the way?
I'm guessing you'll find the motor running at about 4900 rpm
or amazingly high slip.

 

[all duck'd up]

Re: why wont it go FASTER!!!

what is this lip? wouldnt this creat a drag on my prop and should i remove it?

 

[dazk14]

Re: why wont it go FASTER!!!

what is this lip? wouldnt this creat a drag on my prop and should i remove it?
View attachment 130532

Converging ring -Leave the ring alone - part of the design. Thank you for providing the prop pitch. As Steelspike eluded to, too much pitch for the load. You may only be only putting out ~10HP at that RPM.

 

[fishrdan]

Re: why wont it go FASTER!!!

Is the prop in excellent condition?

Yep, is the prop chunked, dinged, bent, gouged, cracked, etc, etc.... I can't really tell as the pic is kind of small and it's hard to see the edges of the prop with the glare and clutter in the background. Missing paint isn't a biggie, we are looking for damage to the prop.

 

[steelespike]

Re: why wont it go FASTER!!!

what is this lip? wouldnt this creat a drag on my prop and should i remove it?
View attachment 130532

Prop pitch is the distance the prop would move through a solid in one revolution Slip is the difference of the prop
moving through a liquid. Depending on the setup 10% slip would be high normal 3% would be amazing.
The higher the percentage the the less it moves with each revolution thus the slower the boat.
W reasonably light boat like yours would generally have normal slip 6 to 10%
Most prop calculators will allow you to figure one indicator out of 5 rpm,pitch,ratio,slip,speed with info of the other4.
We knew your speed, ratio,guessed normal slip,prop size knowing these we could estimate your rpm.
With normal slip your rpm should be about 4900. In order for the boat to be able to go only
19 if the motor was turning 5,500 you would have to have a really high slip I think it would be over 20%.
That why it is important to have an accurate rpm.The more indicators that are accurate the more we can
tell about your setup, As I recall your setup wasn't unusually heavy so if your rpm indeed ends up near 4900
we may suspect the motor because we can assume the slip is in the normal range. As I recall you said the 2 boats are in the ball park on weight.

 

[steelespike]

Re: why wont it go FASTER!!!

We know your buddies pitch,ratio,prop size and estimate 6% slip.
Calculator says he's turning about 5900 rpm reasonable because the hp is developed at 6,000
and the max rated rpm is 6500.
Even at 10% slip its only about 6100.3% would indicate about 5700. Again the importance
of a tach to pin down actual rpm.With actual rpm in the equation the slip would pop right up.

 

[pootnic]

Re: why wont it go FASTER!!!

Maybe it's an optipcal allusion but is the prop bent and twisted in your picture?

 

[smokeonthewater]

Re: why wont it go FASTER!!!

nope that's the angle between the hub and the blade.... playing tricks on your eyes

that prop looks good...... I suspect that it has too much pitch tho.... we'll see what the tach says

 

[steelespike]

Re: why wont it go FASTER!!!

The 2 motors have the same gear ratio,same size props and both rigs are about 570lbs.
Buddy weighs 35lbs less but carries more gear. I suspect the motor.At this point your not likely to find 5 mph in a prop or setup I guess the tach will tell us something.

 

[all duck'd up]

Re: why wont it go FASTER!!!

update... the boat ran like a top this weekend; i guess the new gas lines and screen cleaning worked. it ran 21-22 up river and 23-24 down with just me the duck decoys and gun. at 23-24 it was bouncy in the front so i tried to move forward a little but with the short tiller there wasnt enough for me to stop it. i also had the battery out of the boat completely. next i will bring the motor up about a 1/2 inch to see if there is any increase.

 

[steelespike]

Re: why wont it go FASTER!!!

Boy thats great! Raising the motor may not result in more speed but might soften the bounce a little move something forward just enough to stop the bounce. The less you drag through the water the better.If you want to go for more speed you might consider the Turning Point Rascal or Solace Saturn ss props.The Rascalis an aluminum prop that delivers close to stainless performance.Both should allow maximum height.

 

[all duck'd up]

Re: why wont it go FASTER!!!

Is the bottom clean and smooth?

i used a flat based paint to do my camo would i see a increase in speed if i re-did just the bottom of my boat in a glossy paint?

 

[steelespike]

Re: why wont it go FASTER!!!

Shiny paint might help but it would be hard to tell the difference.
Really need a tach to tell the next move.
Did a little figuring the 10" prop puts you at about 6200 rpm
based on 23 mph and a guess of 6% slip.
A 10" turning Point Rascal "might" get you a little more speed
and a slight improvement across the board.

 

[smokeonthewater]

Re: why wont it go FASTER!!!

i used a flat based paint to do my camo would i see a increase in speed if i re-did just the bottom of my boat in a glossy paint?

No.... in fact you might actually lose speed.... a slick bottom is a slow bottom