Wayward driving

[Vic1]

I have a curious problem that I was hopeful that the guru's of Ausfish may be able to help. My boat (Seafarer Vamp - 5m centre console) is quite difficult to steer straight at very slow speeds, it has a tendancy to wander from side to side to the point that it constantly requires correction to keep it going straight (obviously increasing the degree of difficulty of driving in up on the trailer ). Once on the plane this tendancy to wander disappears completely.

Any ideas???? The boat also requires a far kick in the guts to get on the plane, with one person suggesting I need a foil, could this be one of the causes of my problem???

Look forward to your replys

[blaze]

havnt got a gut ful of water under your floor, exta weight to get on the plane, water slopping when gooing slow making it hard to steer, water moves rearward and stabalises once one the plane.
cheers
blaze

[Vic1]

Thanks for the info Blaze, but no, it happens from the start of the day when their is definately no water at all in the hull

[TOPAZ]

This is a common problem with power boats at low speed.
I used to skipper the Coastal Patrol's Melbourne Training Vessel (12 metre timber displacement ex-army workboat), and it was all over the place at very low speed due to insufficient water flow over the rudder.
With my own vessels - the last one a Swifcraft SeaHawk MxII with 90HP Evinrude it steered best at low speed with the motor trimmed all the way in, which forced the bow down giving more hull/keel in the water.
My current boat (Whittley Cruiser 660/Mercruiser sterndrive) is worse, but I can minimise the effect by trimming in and lowering BOTH trim tabs fully, which once again forces the bow bown into the water.
The other thing you can do, is try not to chase the boat all over the place with the wheel- you will find it develops a pattern of veering slightly each way, and will correct itself to a large degree if left alone. It is very easy to over-correct and make the situation worse.

[Chimo]

Hi Vic1

Its a little hard to make sensible suggestions without some more info please.

The 5m Vamp is essentially a VSea hull with a pod.

Have you asked the manaufacturer?

How long have you had the boat

Who set it up

What motor HP do you have

What revs is the motor doing at idle

What propeller are you running

Is the problem the same no matter how far out the motor is trimmed

Is the motor sitting on the transom or has it been lifted

A fin probably won't change the steering characteristics at idle

Whats different, new motor, different prop, ............

Looking forward to some info


Cheers

Chimo

[Vic1]

Chimo

Answers to your questions


Have you asked the manaufacturer?

Manufacturer of the boat (Seafarer) aren't very forthcoming with much info about anything. Iv'e had a few seperate queries over the past 2 years and haven't been given intelligent responses, so I'd rather go to a forum like this first


How long have you had the boat

2 years


Who set it up

Jet 1 Marine in Parramatta (bought it from a guy in Sydney)


What motor HP do you have

90Hp Evinrude FICHT 03 model


What revs is the motor doing at idle

Not sure, need to check this on the next trip


What propeller are you running

17 inch


Is the problem the same no matter how far out the motor is trimmed

Yes, there doesn't seem to be any major difference


Is the motor sitting on the transom or has it been lifted

On transom


A fin probably won't change the steering characteristics at idle

Whats different, new motor, different prop, ............

Nothing is different, it's just that I've put up with the problem for 2 years and now I want do something about it

Look forward to your reply

[Fat_Chilli]

Firstly - what is the steering system on the boat?

If it is standard cable steering, then your best options are Tele-Flex non feed back steering needed, or the more expensive option of hydrolic steering (have seen them for around $700, maybe cheeper, not sure).

I recently installed the Tele-Flex non feedback steer and it prevents all wandering at slow speeds, now I can trawl in a straight line, cost was $156 for the column, using my existing cables etc.

Hope this helps

[Vic1]

Fat Chilli

I've got hydraulic steering

[Fat_Chilli]

Well that scrubs my thoughts

[blaze]

Have you got air in the steering lines, is there very much play in the wheel
cheers
blaze

[seatime]

As blaze suggests, check for air in the system or insufficient hyd fluid in the unit.
hyd steering shouldn't wander around so noticeably.

if it's not the hyd unit then it may be a simple case of not enough water flow past the leg for it to act effectively as a rudder, and so you're correcting constantly, as suggested by topaz, then the transverse thrust of the prop dominates control.

what's your definition of 'very slow speeds', < 3 knots ?? or faster?

regards
Steve

[Spaniard_King]

Do you have a sea star ram???

best Idea is to go down to the engine and wobble it from side to side to see if anything is loose. There should be minimal play.

My guess is that one of the locking rings on the ram is loose giving you heaps of play

Garry

[peterbo3]

Vic,
Is your hull true? Not the first time a hull has warped in a mould. Try running a stringline along the keel....will quickly show up any faults.
If the hull is straight, is it too heavy at the back end? Podding a boat can change the handling enormously, especially at low speed
when there is relatively little thrust being generated by the prop. Try some ballast up front. Some sandbags or water jerrycans. Start at 100kg & go up to perhaps 150kg. If you have batteries at the stern, can you move them forward on a temporary basis?

[Chimo]

Hi Vic1

Thanks for your answers.

Can you be more specific about the prop please.

Is it Al

Is it stainless

If stainless

is it a Viper

or Raker

Or what?

Thanks

Cheers
Chimo

[Vic1]

Blaze

Not much play in the wheel, maybe 5-10 degrees at most

Gelsec

Slow speeds less than 6 knots

Spaniard King

The hydarulic set-up is a Hydrive Admiral series. I checked the engine and their is absolutely minimal play (when the engine wobbles, so does the rest of the boat )

Chimo

The prop is Al (was painted once upon a time.......) prop still in good nick though

Hope this helps