Roostertail problem???????????
 

I mounted my outboard back on my boat after doing transom, i tested it and had alot of cavitation and roostertail. So i thought it was too high so i lowered it 1 set of holes on the motor, now i got rid of the cavitation but still have rooster tail. I put a flat edge on it in my driveway and the cavitation plate seems to be 1 inch below the keel which i was told would be ok. My boat does not have a bracket, so has anyone ever had this problem? I didn't have any of this before doing the transom and it is driving me crazy. Should i go down another set of holes?

If your doing 60 MPH a rooster tail is a good thing...:)
Is it a prop rooster tail or a transducer or other device hanging on the
back causing the tail ??? Even placement of trim tabs can cause this.
Take a few rear end pics and post them, we might be able to pick
up on whats going on...
Standard on a non bracket transom is an inch above or below the
cavitation plate.. just my 2¢ worth!

Seems to be coming from above the cavitatin plate on the motor area, when I trim the motor up it goes away.

So we know it is not a prop tail!
When trimming up the edge of blade is what causes a true rooster tail
braking the the surface of the water....

Is there an anode or something else mounted on the cavitation plate?

Lets keep digging, we can beat this!! :D

Your 'cav plate should be just above the keel, not below it. Is it dragging through the water? Is the boat loagie and slow in the corners?

http://forums.iboats.com/showthread.php?t=346526

We definitely need pictures! (even if its just to put some circles and arrows on)

When you did the transom, did you change the shape of the running surface of the hull at the trailing edge?

Cheers,
GFS

No nothing on the cav plate at all.

I don't think so i left about a 2-3 in lip all around and did not change any shape of what i left.

Will have pics tomorrow.

I think you are too low. The cav. plate should be about 1/2" to 1" ABOVE the keel IMO....

what about a change in the angle of the transom?

The hull bottom was not disturbed or glassed?

Sandy...good straightforward questions...stop ....your.. scaring me...!!!!
Your Garmin still works I still know how to get home...pigs fly!
Are you running a chopper?
-Fred

No the hull bottom was not touched.

Again i slid in the new transom from up top into the lip that i left so if there is a change in angle it can't be alot.

The strange thing about this is when i am going along i can trim the motor up and this will go away. The thing is that i have to trim it up a bit to high to run all the time. I like running with motor trimmed up when the water is flat, but when it is choppy i have to bring it down due to cavitation.

Entourage,

BRP says you should be able to SEE the top of the Anti-Ventilation/Cavitation plate when you're up on plane and fully trimmed out. I suspect your motor needs to come up at least 1 hole. As others have said, AV plate about 1" above keel should be about right for a transom mounted motor if you have a good cupped prop that bites well. Denny

My fave is the Apollo 4 bl. Bites well. Smooth design on the hub.

This prop made me smile for the lack of "bad" vibrations. I felt a very noticable smooothnesss in my hand.

Far better than a slug of plastic and a bad casting job.

I`m runnin and old sst1 prop now til I sssssssort out another issue.

Spring is here and the cobia are early. Heads up. This is going to be an early year.

86 in Bangor, Me.

80 in WPB.
Cheers,
Us

OK, Sandy stay the coarse.....:p
A.D.D. is setting in.....:rolleyes:
Meds are good, erbs are bad!! :eek:

We will over come!!!;)

Beautiful pilot house. He may benefit from a bow lifter or a 4 blade sliced outside.

Cheers,
Us

Here are a few pics

You are too low.

strick

Agreed. Should be able to come up at least one, maybe 2 holes.

May have discovered the problem. With the weight up front of the pilothouse and the rotten wood I took out of the transsom. There is not enough weight in the stern so when the boat planes out I am getting the spray. I put my fishing vat back in the stern and that added enough weight for it to disappear. Never noticed this before because I never took the vat out.amazing what a difference some weight makes

That's great. Even so I think you'll improve overall performance raising motor to at least where you started and then one more hole. :cool:

Where are my thin branches?

Go up two holes, with a deep V boat, you can actually have it a little higher than the bottom of the boat.

Definitely.

It was probably the flange around the top of the lower unit throwing up the rooster tail. When you put the vat back in the boat you may have pushed the flange under. I would raise the motor two holes and if the prop blows out in a chop at normal running trim (it probably won't), drop it back down one.
Dave

Yes exactly thats what it was. I feel alot better now knowing what it is. I appreciate all the knowledgable thought put in to this from all of you.

Wait, does this mean no pictures? I was really looking forward to them

What pics do you mean? I posted some already. You mean in water pics?

Haha I was just kidding, wanted to see a SeaCraft rooster tail!

No you don't want to see one, cause if you do then you have a problem. Lol.....

Two things come to mind when I see that sweet pilothouse. I would love that up in my home, but how would that affect the CG on a small boat? Beautiful work and I`m sure you love it in your chop, but there comes the weight question? New 4 stroke? I can trim my 20 by asking Jesse to move around. He is young and a good sport. Heavy too.

The waterline looks spot on, so how am I confused?

Strange as this must seem, you might want to try an agressive bow lifter for a prop.

Any prop with a very agressive cup in the tip might work well.

"so how am I confused?"

Sandy, is this a trick question? Just trying to get us to bite, huh? :)

The weight up front these boats with the type of hull actually is better, this boat is 10 times better in the water than what it was with just the windshield. I call it a "roostertail" but it was really a minor spray, but i am very picky. But now it is perfect.
"