HELP ME PLEASE

[danytink]

....I,m a newy here.

Have had a boat for about a month now but has a problem. #It's a 19 foot Sports Carrera Cabin cruiser with a 115 Hp Merc on the back.

When I got the boat I could see where they took the hydrofoil off. #We went out in it and when steering while going along the boat lurched right over to the side i was turning. #I went and bought a new Hydrofoil SE Sports 300 and went down agian to try it out. #This time it was worse and nearly threw my friends into the water?????

The trim is all the way down to the stopps and even when going straight the Hydrofoil made no difference it seemed, because the nose was still sitting up a bit????

Can you please help me before I kill someone????

Dan

[cooky]

a little more explanation or clarity would help. Not quite with you. Are you saying small movements in steering wheel are causing this or full lock turns?

[Camo]

Hey Dan,

I don't know what a Sports Carrera Cabin cruiser looks like, or what type of hull it is, but there may be a reason why the Hydrofoil was taken off by the previous owner. I don't claim to be any expert but I do know that on certain boats, Hydrofoils can be dangerous. I have heard of some boats that have nearly capsized because they were not fitted correctly. In fact I have read that some of the larger boat builders advise against putting them on their boats. Like Cooky says without further explanation its hard to give you any meaningful advise.

I don't know what type of boating experience you have, and I don't want to insult your intelligence, but boats do lean in, like a motorbike when you turn, some more than others depending on hull type or configuration. (I know cats don't lean in) This might be increased by the weight distribution in the boat, where were your passengers standing when you turned? Wind can also cause cabin boats to lean.

For what it's worth, I would suggest giving the Hydrofoil the flick. Have a look at weight distribution in the boat, and get a marine mechanic to check how the motor is fitted. It may be off centre or too high. If all that fails to correct the problem you might have to give consideration to having trim tabs fitted.

Best of luck,

Camo

[DaveSue_Fishos_Two]

It would pay to check the height of the cav plate. It should be about 1 inch below the hull.

Cheers
Dave

[danytink]

......sorry fellas - more details. #The hull is a standard fiberlgass "V" shape with ridges running along the bottom. #I bought the hydrofoil because I thought it would fix the problem that I already experienced without it. #When I put on the new Hydrofoil it seemed to make it much worse. #The hydrofoil is fitted as per instructions but the problem is not the foil I believe.

If I go from a standing start with the steering wheel turned with a fair bit of throttle - no worries. #It's when I am going along in a straight line the boat has a slight lean to my starboard side (the side I'm steering from), and when I go to turn it kinda lurches over to the side where I am turning into but keeps going soughta straight. #The side roll is so violent it really tips us around inside. #I actually thought we were going to capsise it was that bad - we were nearly vertical.

Weight distribution was fine at the time and I don't think it was on a natural lean into the corner because it didn't turn but seemed to be thrust onto it's side. I have a little bit of experience but even my mate said while we were travelling along, "are boats supposed to do this" - he was referring to us steering in a straight direction while the boat was leaning over to my side in quite a radical way. There was no wind.

I checked the cavitation plate when I got home because I read about that on your site and from a straight rule the plate is level with the bottom of the "V" on the rear of the hull, probably more below it than above but pretty well spot on. # More info????

[lippa]

we problems like that mate you should get an expert to check it out for you.
hope its an easy fix.

cheers

lippa

ps

cooky, can i borrow your deckie's? please!!!!!!!!!!

[onerabbit]

# # Ahem, ;D ;D ;D

# # Move over Lippa, I asked to swap deckies ages ago, ( even sent a photo ) mine must have been to rough around the edges, even though he gets good fish. ;D ;D ;D ;D ;D

# # Muzz
# #
# #

[familyman]

Does the boat float level at rest with no-one on board?if so then weight distribution is ok.
Does the boat behave the same in both directions ie left turns and right turns?If so then motor centre is probably ok ie motor is in centre of hull and torque tab is adjusted properly.
Is the boat equally hard to turn in both directions? Ie same pressure on the steering?
Take the foil off,having done that is the lurching more or less?

I am assuming you are not trying to drive the boat like a ski boat so turns will be gentle and not really full throttle.
From everything you have said it sounds like you do not have enough weight in the boat ,at rest the chines (flat bits at the hull edges)should be just under the surface at rest,any forward movement should cause the hull to lift these out of the water.
If the hull is too light then as you turn the reduction in hull depth in the water will cause the hull to fall onto its flat surfaces to regain bouyancy.
If the boat is a deep vee with a variable deadrise front to back ie to bottom looks twisted when viewed from the rear ,the boat will fall onto the the steeper sections due to not enough weight in the rear.That would be my suspicion,115 hp for a 19' sports cruiser is a bit light on both power and weight.
Put more weight in it to make it sit correctly at rest and then try again .
With regards to trim unless the boat is running into a chop the the nose should be trimmed up to get the front out of the water and increase the weight bias to the rear of the boat other wise it will want to steer with the nose not the back ie it will be VERY hard to get out of a turn once in it. Try this process and see what happens .
If you can still get enough performance out of it with more weight then you are lucky :) but I have a sneaking suspicion you will want about another 50-60 hp or a 150 hp 4 stroke(heavier ).
That should please the bank manager :o
Good luck and if you want any more just yell.
cheers jon

[cooky]

cooky, can i borrow your deckie's? please!!!!!!!!!!

Why's that?

oh - because they catch nice fish ;)

They are talented with rod and tackle.

[dnej]

Rod tackle,what sort of rod tackle?
David

[arni]

I have simular boat with 135 merc I had had same problem when first bought it, until I got used to triming the motor to get the front out of the water now all good

[MulletMan]

Have you had a look at the small directional trim tab under the back rear of the cavitation plate?
If the boat doesn't want to stay nice and straight ahead, this tab is used to adjust the left/right tendancy. Could it be so loose that it is maybe swinging all aver the place? Doubt this is the problem but worth a look nonetheless.
Think Familyman above put up some good suggestions to finding the problem so not much left to guess about.....
I suppose the right propeller has been fitted eh? I would imagine that on a 19 footer you should have something like a 17 x 15" prop (RH) on the merc?
With a great deal of care, I would trim the motor UP until you can hear it just starting to cavitate and try a VERY GENTLE turn both ways and see what happens.
A prop near to cavitating when you chuck a serious turn can get yer heart hammering a bit faster than normal ..................
Another dumb question ..................... I assume it is a long leg outboard and not a short leg that someone has fitted?
You would have a ton of fun with that sort of motor on a 19 footer!
I just have a gut feeling that there is something wrong with the outboard leg but certainly looking forward to hearing what you will eventually discover!!

[blaze]

some pics of the back of the boat would be good. Havnt got a moving balast have you (water trapped on one side of the hull)?
cheers
blaze

[FNQCairns]

Your probably running it at speed with too much -ve trim even if the numbers are best at your setting sometimes a person must go where the hull 'feels' better.
I agree with family man a bigger engine or some extra weight rearward would probably see the problem go away.
In the mean time re-trimming the little torque tab on the engine to suit the speed you most commonly run at wouldn't harm anything and will probably help, with the increased use of hyd and no feedback steering the driver is further separated from what his boat is actually doing, try playing with that trim tab and see how it goes and dont forget to try a spot more +ve (nose up) trim.

Is this one of those light-ish US boats that can be ordered with an inboard-outboard fitted? sometimes it's cheaper for the manufacturer to only make one version of a hull, sometimes it suits one application better than another.

cheers fnq

[danytink]

...thanks for all suggestions. In answer to a few of your questions;

...the boat floats nice and level and chines are under water level and the boat does rise at the front when applying throttle

...The enging weight is pretty heavy and pulls the back of the boat down so that water flows into the drain holes in the compartment when I stand at the back of the boat

...the boat behaves in the same way in both directions but moreso on the right side

...when the foil was off it lurched less
...not trying to drive it like a ski boat - just turning slowly
...it is a deep "v" at the front but shallowing out to the back of boat

...if anything, the boat feels as though the nose is coming out of the water too much - ie angle is about 30 degrees

...I can't even get the boat into a turn while going along let alone get it out of a turn

...directional trim tab is secure

...I will tell you one thing,...the yoke (dunno what the thing is called?), the part where the engine swivels on is sloppy. The bottom "U" clamp looks worn and wobbles on the shaft a bit - say about 5 ml slop?? Surely this small movement though wouldn't do what it does.

...engine seems to be reving high but not much propulsion - prop is a 3 blade Mercury Vengeance 18P???

...tis a long leg

...the motor is trimmed down as far as it can go when this happens - should I put a setting bolt throught the setting holes and try it again???

...not one of those US boats

...funny thing you should say about a water balast inside - scary, how do you check that??? I always remove plugs at ramp on way home and they drain good???

As much info as I can give you at the moment - thanks again.

Dan

[PMC]

Take it to a dealer to check out, before someone gets hurt?

[blaze]

Hi Dan
Unlikely to be water, some boats have air tight chambers in the subfloor.
short of cutting inspection ports
You could try rocking it on the trailer and if there was enough water in there to be the cause of the problem I think you would hear it sloshing about.
cheers
blaze
ps might pay to engage the services of an experience boatie/ survey/engineer and have it checked.

[finga64]

...I will tell you one thing,...the yoke (dunno what the thing is called?), the part where the engine swivels on is sloppy. #The bottom "U" clamp looks worn and wobbles on the shaft a bit - say about 5 ml slop?? #Surely this small movement though wouldn't do what it does.

Yep they're stuffed. 5mm is an awful lot of play. That would equate to a big movement either way of the motor at the prop. Thus tending to accentuate the small turn of the steering wheel. Could be likened to driving a car with worn out ball joints and tie rod ends with a stuffed steering rack thrown in. ie turn the wheel a little bit...nothing happens...turn a little more..yahooo...swing the wheel back the other way to compensate ...and then over compensate...

Amasing just how much those bushes affect handling. Originally I couldn't control the tiller Tohastu with 2 hands, changed those pivot bushes and bob's your uncle. Good as gold. #:)

Combined with the trim issues this may be your problems. (but don't quote me on that)

Hope you find the problem soon matey

[danytink]

....will try these suggestions - thanks heaps fellas....

Dan

[familyman]

Congrats scott on the platinum membership :o
cheers jon

[akman1]

just going back to what Blaze said,I found on my glass boat about the water tight compartments and if one of them get water in,it steers like my old man's b model mack,pick a corner and guess.for what it's worth..

[danytink]

....yeah, shook the boat rigorously on trailer and listened - nothin.....

I think Finga is right if there's a gut feeling in this...will get yoke bushes renewed and try again....thanks.

[mcgilld]

This wouldn't be the sole cause of a real problem like you describe, but the only thing not already mentioned that might add to the problem is free surface effect in your fuel tanks (ie. large cross-floor tank with no baffles - same issue as a body of water underfloor moving quickly abeam when you attempt a turn and overtrenderising the boat).
Have you considered your 80-100kgs making right turns worse when testing on your own??
Cheers

[finga64]

Yep, the old tank slap is a pain. I learnt from experience on the old motor bikes. Used to scare the begeegus out of me.
But in this case you'd also hear it when he shook the trailer/boat. That is if there was any fuel in it of course.
Good idea to check though :)

[MulletMan]

Geeez, what a pickle eh?

I still reckon there is so little of the boat "in the water" that you are basically turning on the prop so to speak. If it is as stern heavy as you say then at speed whereas a boat would normally have about 60/75% of the hull in the water on the plane, yours could be almost all out of the water bar the last metre or so forward of the leg/prop area. In this configuration, the vessel is going to be very very twitchy to any steering inputs and as there is very little "water drag" on the hull, she will whip around real fast.

I still reckon I would chuck a couple bags of sand in the forward bow plus a couple passengers and see if you get the same problem with the nose well down.

That won't fix the problem unfortunately but might help to identify it all the same.

Don't confuse the electrically controlled trim angle with the adjusting bracket on the transom. The latter normally has about 6 to 8 holes in BOTH the brackets with an adjustable pin between them. This should be in the hole CLOSEST to the transom.

It could also be a combination of problems and the loose mounting would not be helping either.

I reckon you should get some of the AUSFISH guys to find a volunteer to go for a ride with you as there are some pretty cluey members here.

Think we are all interested in solving this one!

What suburb do you live in and where do you launch?

[finga64]

That's the go TPP :)

[bitemybloodyhook]

"Don't confuse the electrically controlled trim angle with the adjusting bracket on the transom. The latter normally has about 6 to 8 holes in BOTH the brackets with an adjustable pin between them. This should be in the hole CLOSEST to the transom."


this is a little off topic but i am new to boating, what is the difference between the electric trim and the manual trim on the bracket??

[Basil2]

Could it be that you have a large fuel tank on the right hand side of your boat,maybe the fuel is slopping about,exaggerating the effect when you turn right. Good luck

[MulletMan]

Sorry for the confusion BiteMyBHook!
The electric trim operates off the throttle normally via a two way switch and physically lowers or raises the entire leg itself for on-water trimming or right up if trailering.

The fixed bracket adjusting assembly is normally put in the correct position after motor installation and then never touched again.

You can see it on this weird looking pic attached. The three adjusting holes are right in the middle of the pic and it looks like the pin is in the left hand one??

This is about the normal position on the inner hole though some boats and motors will vary from this one. The further you bring the pin out then the higher the nose will be on the water when planing.

Once you get that bit right then the electric trim works in/out from that position.

[finga64]

Gees that's a serious prop guard TPP.
It's nearly a jet conversion :D.
I take it that that motor is for a rubber ducky as it's got the guard and extended tiller handle in the middle. :-?

[MulletMan]

At a guess I would say it is a jet unit!
The pic comes from the USA and I know some manufacturers had a fiddle with those jets for shallow water work. No way a prop would work in that enclosed space I reckon.......
Interesting all the same eh?