My first boat - buying tomorrow fingers crossed (advice pls)

[Bigplumbs]

Don't think anyone mentioned it yet. but the most annoying thing you will find with a boat like this on the river, is that it won't track straight.
You will find initially that you are snaking along, going left and right as you try to correct the direction of the boat. And you might well think something is wrong.
This is usual, and with practice you will find that you are over compensating your steering corrections, and in time find you will need a lot less input to the steering than you initially thought.
Just a heads up for your first outing

It is because you are at low speed in a boat that is designed to go fast and it has no rudder. This happens on all outdrive boats. There are things you can buy to fix to the leg that will help but on my Sealine S24 on the broads I just learnt to live with it. Interestingly if you are heading into the tide or flow it is not so bad. Fact of life and very odd at first but ok once you suss it. This does not seem to happen with outboard motors so bad

 

[Bigplumbs]

Not 100% sure, but it is at least partially related to prop Torque. By 20ft bowrider was particularly bad, my 25footer now still does it, but less so.

Not torque. My Kad 32 Sealine S24 has a contra rotating duo prop and it is just as bad

 

[Bigplumbs]

Aah, I know that prop design has a large influence on torque steer, whether they are bow lift or stern lift, whether cupping has been added etc. The shape of the thrust cone. Some RIBs with outboards have their engine offset to compensate, not possible with a sterndrive. Latter probably a subject for a separate thread.

It is nowt to do with the Prop...... This is going up a complete blind ally

 

[limecc]

It is nowt to do with the Prop...... This is going up a complete blind ally

Morning BP. You are plainly wrong. Shall I give dozens of references from people who have their experiences in this and other forums? I'm prepared to do that and am passionate about the subject. Just start another thread on the topic and let's go.

 

[TonyBerkshire]

And with an in/outboard you get a sterndrive.
The spreadsheet hold a lot of info - also tells that for multi-year periods nothing was done.

BTW had a Sea Ray 160 with Mercury 115 hp outboard "2+2 version" and non bow-rider for 14 years. Kept mint in and out at all times, loved it.

Brill... whats the hp on the one I have bought?

 

[Bigplumbs]

Morning BP. You are plainly wrong. Shall I give dozens of references from people who have their experiences in this and other forums? I'm prepared to do that and am passionate about the subject. Just start another thread on the topic and let's go.

Do what ever you want but I suspect you missed my Post about my Contra Rotating Duo Prop doing it just as bad. I am afraid I am only interested to hear from people who have an inboard engine on a stern drive not theory that you have copied and pasted from elsewhere. Why on earth you don't confine you comments to your own experiences I know not...... Have you ever had a stern Drive boat with an inboard...... I have had 2 so know a little of the real world in this situation.

You have been boating for quite a short time and had I think 2 small boats......... Wait till you have more experience perhaps

 

[Bigplumbs]

Brill... whats the hp on the one I have bought?

If it is the 3 ltr Mercruiser it is about 125 - 135 hp . Plenty of power in that boat

 

[TonyBerkshire]

If it is the 3 ltr Mercruiser it is about 125 - 135 hp . Plenty of power in that boat

Oh ok thanks

 

[TonyBerkshire]

So is this possible with this engine and boat / am I allowed to do this in the uk?

 

[limecc]

Do what ever you want but I suspect you missed my Post about my Contra Rotating Duo Prop doing it just as bad. I am afraid I am only interested to hear from people who have an inboard engine on a stern drive not theory that you have copied and pasted from elsewhere. Why on earth you don't confine you comments to your own experiences I know not...... Have you ever had a stern Drive boat with an inboard...... I have had 2 so know a little of the real world in this situation.

You have been boating for quite a short time and had I think 2 small boats......... Wait till you have more experience perhaps

Bigoted personal attack BP.
Personal research and the experience of others count for nothing then.

 

[Bigplumbs]

This short video is on my 115 hp outboard 17 ft bowrider. With your engine you could expect similar performance to this (A little less I suspect) if yours in an 18 fotter

 

[Bigplumbs]

Bigoted personal attack BP.
Personal research and the experience of others count for nothing then.

No attack intended. Research is fine but personal experiences are of course better. I understand you are looking at a larger boat with an inboard and outdrive. If you get this you will find out about this issue. And if you go and mess around with props all you will do is cost yourself money and achieve very little..... I was actually trying to help

 

[Bigplumbs]

So is this possible with this engine and boat / am I allowed to do this in the uk?

View attachment 128301

That might be a bit of an issue on the Thames

 

[ChromeDome]

Brill... whats the hp on the one I have bought?

4 cyl. 3 litre and 135 hp, must achieve 4400-4800 rpm at full throttle under normal load (and will have most hp at 4800). Ol' fashioned carburettor as opposed to injection.
Sterndrive would be Mercruiser Alpha.

Ability to pull toys (and achieve speed) will depend very much on the propeller dimension and the boat GW is crucial (where a prop's pitch equals gears on a bike: Too much pitch and you wont accelerate fast or pull hard, too low pitch and you won't get the highest top speed).

US boats by default commonly are powered in aim of approx. 30 knots top speed, but the calculation is based on "135 horses can push xx load to yy speed". The by far easiest performance gain is by removing unneeded/unwanted weight!

 

[chillee]

Not torque. My Kad 32 Sealine S24 has a contra rotating duo prop and it is just as bad

ahh true, I have the same. Didn't think of that

 

[Bigplumbs]

Tony

When is it you are collecting this new boat of yours ?

 

[Bigplumbs]

4 cyl. 3 litre with 135 hp. Ol' fashioned carburettor as opposed to injection.
Sterndrive would be Mercruiser Alpha.

I suspect it will be the Alpha 1 Gen 2 outdrive. These were by far the most common with a 3.0 Ltr Mercruiser

 

[TonyBerkshire]

That might be a bit of an issue on the Thames

.... the Solent?

 

[TonyBerkshire]

Tony

When is it you are collecting this new boat of yours ?

This Saturday fingers crossed. I was going to buy another car .. a 4x4 today... went from a Audi Q7, to Land Rover discovery 4... but a colleague just talked me out of and advising I should buy something else? So going to take my time and for now I am just going to drive up in my car and get a towing company to bring it back down after I have inspected it with the marine engineer.

 

[ChromeDome]

I suspect it will be the Alpha 1 Gen 2 outdrive. These were by far the most common with a 3.0 Ltr Mercruiser

Yes, Gen 2 came in 1991 and still(?) in production.

So if the original drive is still fitted, you're bound to be right.

Technically much like an outboard lower leg without clutch