Balance in a boat

[grousehunter 61]

I have a 14 foot Crestliner, the transom is small ( not wide ) it is pushed by a Evenrude 35 big twin, ( heavy ) I also have the gas tank in the back ( left side) and the battery ( right side ) we have runabout seats up front, two facing front and two facing back. If you were to divide the boat in half, the front seats are just forward of center.

Here's the problem, I can't get the boat to get up on step, it runs great and its fast, but the rear stays down and the bow is air born at speed, not the way I like it. I need to redo the seats so here is my thoughts on it. Cut the seats in half, padded seats facing forward, and replace the rear seats with a bench, attached to the back of the front seats, Hope that makes sense. Then move the fuel tank up and under the bench seat along with the battery. Does this sound like the way to go, any help will be appreciated. I know nothing about how a boat should be balanced to operate at the best preformance...

 

[ziggy]

Re: Balance in a boat

do you have the engine trimmed all the way down (in)?

 

[grousehunter 61]

Re: Balance in a boat

Its not all the way down, I changed it around and its on the best a angle for the way the boat is now. Last summer we played with it at the lake and set it where ran the best........

 

[ziggy]

Re: Balance in a boat

if yer gonna move the weight around. i think i would try to simulate the weight change prior to cutting things up, like seats.

here's an article on trim. http://www.clubmarine.com.au/internet/clubmarine.nsf/docs/mg19-2+technical
since you don't have power trim, your likely to have to find a happy medium for your manual selection of trim angle to the engine.

 

[Black as]

Re: Balance in a boat

I have a 14 foot Crestliner, the transom is small ( not wide ) it is pushed by a Evenrude 35 big twin, ( heavy ) I also have the gas tank in the back ( left side) and the battery ( right side ) we have runabout seats up front, two facing front and two facing back. If you were to divide the boat in half, the front seats are just forward of center.

Here's the problem, I can't get the boat to get up on step, it runs great and its fast, but the rear stays down and the bow is air born at speed, not the way I like it. I need to redo the seats so here is my thoughts on it. Cut the seats in half, padded seats facing forward, and replace the rear seats with a bench, attached to the back of the front seats, Hope that makes sense. Then move the fuel tank up and under the bench seat along with the battery. Does this sound like the way to go, any help will be appreciated. I know nothing about how a boat should be balanced to operate at the best preformance...

You may need something like this. http://cgi.ebay.com.au/SE-SPORT-HYD...AU_Boat_Parts_Accessories?hash=item2c537c054c

 

[grousehunter 61]

Re: Balance in a boat

Thanks for the link, very interesting. I will play with it again this summer, but I do need new seats......

 

[grousehunter 61]

Re: Balance in a boat

Black as thank you also, I thought about those but never talked to anyone that used them. Do they really work..

 

[Boatist]

Re: Balance in a boat

Is this boat Aluminum or Fiberglass and how heavy is it?
I would start by moving the motor pin one hole farther foward and see if it improves.
You say it is fast but how fast? Do you have a GPS to find the speed??
Normaly it must reach 18 to 20 MPH to get up on plane.
Is the motor down on power and not reaching enough speed to get on plane?
Before I made any modifications I would check the speed and remove all the weight possible.
What is the condition of the bottom? Is it clean with no growth?
If aluminum does it have a hook on the bottom?
Has it ever been able to get up on plane? If so what changed?

Things that will stop a boat from planning.
Too much weight, Too much drag on the hull, Not enough power, Motor trimmed wrong,
Wrong pitch prop.

All boats gain weight over time. The thing we add and maybe wood or Floation soaking up water.

 

[Black as]

Re: Balance in a boat

Black as thank you also, I thought about those but never talked to anyone that used them. Do they really work..

Yes they do work, have put them on the last 2 boats Ive had and they do make a difference, just make sure you buy the right one to suit your boat

 

[ddrieck]

Re: Balance in a boat

What is your transom measurement and outboard mid-section length? If your running a 25'' mid-section on a 20'' transom or a 20 midsection on a 15'' transom your lower unit is to far in the water and causing to much drag. If this is the case, you will never get the boat to break over and get on plane.

 

[5150abf]

Re: Balance in a boat

So there is you, a battery, the engine and gas all in the back, something needs to go up in the bow.

Move the gas and the battery to the bow and it should ballance out real nice.

Had a 12' jon and ran it like that and it almost sat flat in the water, you just have way too much weight in the rear, shift the weight and she will run alot better.

 

[grousehunter 61]

Re: Balance in a boat

ddrieck, you may be on to something, never thought about how far down the motor shaft was. Here is a picture of the boat from the rear.

If thats the case, I could make the transom board a little taller to set the motor up. Where should the prop be in relation to the bottom of the boat ?

 

[Home Cookin']

Re: Balance in a boat

you need a short shaft; consider replacing the motor with a 25 or if you can find one, an old 33. What does your rating plate say? 35 seems big for a 14, although you do have steering.

 

[grousehunter 61]

Re: Balance in a boat

It's rated for a 35 hp. The motor is a 1958 Evenrude,Big Twin, the boat is a 1959. Later in the day I will messure the transom and check just how far the prop is below the boat bottom, what is Ideal ?

 

[grousehunter 61]

Re: Balance in a boat

Ok, I measured the transom and it is 16 inches, I measured the motor shaft, from the power head to where it bolts on to the prop housing and it's 16 inches also, the photo must be an optical illusion. The distance from where it bolts on to the center line of the prop is 11 inches, the cavation plate ( think that is what its called ) sits 1/2 inch below the bottom of the boat. I think I need to look at weight distribution in the boat, not sure what the motor weighs ( 35 hp Evenrude ) but it got to be over 150 lbs, full tank of gas 50 lbs ? 20 lbs for the battery, so its got 220 lbs on the rear of the boat. the transom is 51 inches, the boat weighs 200 lbs itself, I weigh 250, the wife 125, two chessies at 85 each , so we are at 965 lbs. I think moving the fuel tank to mid boat along with the battery might be a good thing.