Set up problem

[bloodline]

Newbie stuff here. Bear with me...

I have a 15' Flats (fishing) boat with a 115 opti. The bottom is padded with a little bit of hook. I have run a few different props and bow lift is a struggle. took a 24 Laser to the local prop shop and got some cup added. I finally got the bow lift I wanted but I also got a new problem.

Around 55 mph it violently blows out and tries to eject the driver :eek:. I've tried less trim. Same thing.

A straight edge on the bottom hits the 3rd hole from the top on the water pickup.

Ideas?

[981m]

Thats a lot of power on a 15' boat, what make? I run a Hewes Bonefisher with a Yahama 90. push the tabs down and it jumps on plane. Top end is about 45.

[bloodline]

BC 151

http://i493.photobucket.com/albums/rr294/eatapogy/bc1.jpg

[981m]

I don't see any struts for trim tabs, adding a set of tabs would get you on plane in a short distance. I did see a jack plate, you may be raising the engine to high and the prop will blow out. Most flats boats are set up to get on plane fast to avoid prop damage to the sea grass and top end is not a major consideration. On my Hewes I did have an issue with lack of bow lift but that was corrected when I raised the engine. Its been a while since I looked at the prop, I cannot remember what I am running.

[bloodline]

no issues with planing. Doesn't need tabs.

It just keeps trying to eject me.

[981m]

You might want to try lowering the engine. Looks lihe some good Redfish water in the photo.

[bloodline]

yes and yes. Thanks.

[981m]

Keep me posted you can always contact me at dmartino@burnip.com

[john miffco]

from a builders point of view
its a true flats fishing boat
not a high performance speed boat or a semi shallow running bay boat
these 2 hulls have natural bow lift
a true flats has very minimum by design

a flats boat is designed to float high to get across and take off shallow water
ride flat,,,,,,,,,not to let transom drop down to go across shallow water
and take off flat,,,,again not to let transom drop

a speed boat lifts bow and allows air to go underneath
to lift whole boat up for less water drag
and tramsom naturally drops down during this process in take off and running from weight of hull directed towards tramsom and also allows gearcase to track for higher speeds

so its a see saw effect
its hard to have both worlds and have either boat perform to its max capabilities

by adding all the bow lift to the prop
some of the boats characteristics have been compromised
as you have found out
by adding major lift to prop,,bow is higher along with the rest of the hull
air going underneath lifting,,,so now tramsom is blowing out at higher
not safe,,,again as you found out
you must find the happy medium
gaining a tad of bow lift for better ride
without lift too much to kill
the flat design to go across shallow water

a flats boat is for fishing the flats
but going across bays to get there
is not a very soft ride
sugest taking some of the bow lift back out to take away the blowout problem created
and slow down across the bays,,,,,,,,,less hammering of you and the hull
a bay boat is smoother in the rough,,,,not real shallow running
flats go in skinny water but not so smooth across the bay
just my thoughts
john

[bloodline]

I've been told to lower the motor a 1/2" and also been told that the gearcase is blowing out and I need to twist the skeg or add a tab on it to fix that. Can a gearcase blow out at 55?

[looseunit225]

is it doing this?

http://tinypic.com/player.php?v=82bdfed&s=1

if this is what its doing you have no idea what its like at 85mph and it does it!
its usaully what happens when i accidently rest my foot on the trim up button and not relise!

but also can be caused by too much bow lift and the boat has a suction to the water and once you break the suction it lifts!

have you tryed to drive it over slightly rough water i mean like rippled water! it could break the suction for you and it would tell bus why its doing it!

[bloodline]

are you dragging a skier? Nuts.

No, it doesn't do that.

Multiply that times 5 and drop the bow.

[looseunit225]

yeah thats a skier on the back! hehehe i love it

well if its worse than that i would say the hull is being sucked to the bottum and if you have a hook in the bottum thats where it would be coming from and as soon as you get to the speed where the air starts to travel underneath the hull to the starting point of the hook than it will back the suction and make you outa control!

[bloodline]

Update- lowered the motor 3/8". Problem solved. Rock steady now.

[looseunit225]

good stuff

[981m]

Now it time to fish

[bloodline]

Nah. you know how it is. I just had my prop tweaked again this morning. Probably gonna move the motor up an 1/8th. Contemplating flipping it and working on the bottom...

It is a sickness.

[looseunit225]

your contemplating flipping the boat while you drive it on the water or onto a set of tressels to work on the bottum hahaha!