Petrol Or Diesel et al from A Beginner

[Davinder]

Hi All,

I am totally NEW to boats and have three very basic questions before I purchase my first boat. Should I go for petrol or diesel engine; should I go for single or twin engine and would a Sealine S28 be a good first choice?

I am looking to use it on the river and not on the coast.

Sorry but I am a total novice and cannot afford to make an expensive mistake.

Thanks in advance for any advice.
Davinder

 

[neale]

You would probably be better off posting this in the MoBo forum.

In summary.

Diesel boats more expensive to buy but cheaper to run and easier to sell.

Petrol boats cheaper to buy, more expensive to run and harder to sell.

Single engine much cheaper to service and cheaper to run than twin.

Twin engines provide some comfort that you have a second engine to get you home.

If the boat was only going to be used on the river I would say a single petrol is fine. It will be the cheapest to buy, the cheapest to service and at river speeds won't be very expensive to run.

If you ever think you will want to do some serious sea mileage I would say it has to be diesel and twins would offer added security, although a well maintained single diesel can also make a good cruising boat.

On a single engined boat a bow thruster would make handling less fretful.

The S28 would make a good first boat but it depends on how many people you plan to have on board. Two adults it is perfect. Two adults and one child it is fine. Two adults and two kids it isn't the best. The older 290 with two singles in the mid cabin would be a better layout for a family of four.

This is all in my opinion but based on owning a single petrol, a single diesel and a twin diesel, the latter an S28.

 

[AntarcticPilot]

Petrol is explosive; diesel is not. This is, of course, a generalization - but that's basically why diesel power is favoured.

 

[SAWDOC]

Diesel without a doubt. Safer and most likely lower running costs. Fuel costs on large petrol engines can be a serious consideration.

 

[neale]

Petrol is explosive; diesel is not. This is, of course, a generalization - but that's basically why diesel power is favoured.

I don't think this is true. Diesel is favoured because until recently it was considerably cheaper than petrol and you got more MPG out of it. It is also much more widely available on the coast outside of the Solent. The explosion risk in petrol boats is grossly overstated and easily managed with some basic common sense.

Diesel without a doubt. Safer and most likely lower running costs. Fuel costs on large petrol engines can be a serious consideration.

Apart from when used on a river which is exactly what the OP is intending to do.


I am usually a big advocate of diesel in MoBos, but in this case there is defiantly a case for the OP considering petrol unless, as stated in my previous post, he is planning to go to sea. On rivers diesel engines are often noisy and smoky, petrol engines much less so.

 

[johnalison]

A major consideration on the coast is the availability of each fuel. Some years ago I used to waste hours walking around towns looking for petrol-stations as the harbours only sold diesel. I don't know how things stand on inland waterways but it may be worth bearing in mind.

 

[theoldsalt]

Can't anyone dissuade the OP from buying this type of MoBo.

It would be like puting a novice driver with no experience into a powerful sports car. Utter madness.

I suggest he buys a displacement boat with a modest engine and gets some river experience for a couple of years first.

This type of boat is difficult enough to handle even with experience

 

[Bobobolinsky]

Diesel is safer without a doubt. Second boat in a year with a petrol flash over at the Marina. Fortunately it was just that, no one hurt and just the electrics fried

 

[neale]

Can't anyone dissuade the OP from buying this type of MoBo.

It would be like puting a novice driver with no experience into a powerful sports car. Utter madness.

I suggest he buys a displacement boat with a modest engine and gets some river experience for a couple of years first.

This type of boat is difficult enough to handle even with experience

Sorry but that is simply not true. If he is going to keep it on the river he will be limited to 5 knots ish anyway so what difference does it make what boat type he does it in. A sterndrive boat is arguably easier to drive than a single shaftdrive, and certainly no more difficult.

 

[neale]

Diesel is safer without a doubt. Second boat in a year with a petrol flash over at the Marina. Fortunately it was just that, no one hurt and just the electrics fried

What caused these two boats to flashover?

Petrol is save as long as there are no leaks in the system and the refuelling is undertaken with care and consideration.

 

[Bobobolinsky]

What caused these two boats to flashover?

Petrol is save as long as there are no leaks in the system and the refuelling is undertaken with care and consideration.

The first boat had twin Ford Pinto engines. Had service and BSC week before, one of the pintos "popped back", ignition fault. Burnt it out completely. Second one, the fire damage is at and around the batteries, so source of ignition, battery, spark.

 

[AllanJ]

Sorry but that is simply not true. If he is going to keep it on the river he will be limited to 5 knots ish anyway so what difference does it make what boat type he does it in. A sterndrive boat is arguably easier to drive than a single shaftdrive, and certainly no more difficult.

Can't really compare as I have only owned a twin stern-drive. It's actually and below 5 knots that it begins to be harder to control. My boat (Sealine F33) is only idling at 5kts.
Having said that, with two engines I can turn the boat in its own length which may be handy in tight situations.

I agree that a bowthruster would be useful, but am not prepared to enter any debate about it

 

[theoldsalt]

Neale,

So what is the point of having a boat with a 250hp engine capable of 20knots (or so) being used on a river when the speed is limited to 5 knots. It will probanly be capable of exceeding the speed limit with the engine at tickover.

 

[neale]

Neale,

So what is the point of having a boat with a 250hp engine capable of 20knots (or so) being used on a river when the speed is limited to 5 knots. It will probanly be capable of exceeding the speed limit with the engine at tickover.

The most obvious reason would be because he wants to go to sea at some later stage, but it might also simply be that the OP likes the boat, design and layout, and that they are all fitted with at least 250hp. I have the same boat with a total of 300hp and have kept it on the river this year. It is well below 5 knots at tickover.

 

[neale]

The first boat had twin Ford Pinto engines. Had service and BSC week before, one of the pintos "popped back", ignition fault. Burnt it out completely. Second one, the fire damage is at and around the batteries, so source of ignition, battery, spark.

The first one should have had a flame arrester fitted but in either case there should not have been petrol fumes in the engine bay to ignite. The problem was not the fuel, but the fumes. Why were they there? Either a leak or careless re-fuelling I would suspect.

Could the second one actually be battery gases that have ignited, rather than petrol?

 

[CreakyDecks]

.. there should not have been petrol fumes in the engine bay to ignite. The problem was not the fuel, but the fumes. Why were they there? Either a leak or careless re-fuelling I would suspect.

Isn't that the whole point? Obviously petrol is perfectly safe until something goes wrong. I suppose the same could be said for plastic explosives. The funny thing is that plastic explosives are probably harder to ignite and yet how many of us would want the stuff on our boats?

 

[Niander]

The vast majority of cars are petrol and i dont see a big problem of them blowing up all over the place!
as said so long as extra care is taken i think petrol is fine...[the fact i have a classic inboard petrol engine is irrelevant]!
thats in a sailing boat as main engine is free wind!
otherwise id say diesel ..except cheap red seems to be disappearing fast!
so id say get a sailboat!

 

[AntarcticPilot]

Isn't that the whole point? Obviously petrol is perfectly safe until something goes wrong. I suppose the same could be said for plastic explosives. The funny thing is that plastic explosives are probably harder to ignite and yet how many of us would want the stuff on our boats?

Agree. I have experience of handling explosives - they are very safe compared with petrol.

Petrol forms an explosive vapour with air; diesel doesn't. Petrol vapour has a low flash point; you can put matches out by dipping them in diesel (don't try this at home!). Make a small mistake handling petrol and you have a bomb; make a mistake with diesel and you have a nasty smell. Boats often have inaccessible fuel tanks; leaks can develop unseen and without warning. It happened to me; I am thankful it was diesel and not petrol.

 

[Niander]

i am putting in all new fuel line can only do my best
and a drip tray under carb
checked daily before starting engine or turning on electrics.

 

[oldsaltoz]

Petrol is explosive; diesel is not. This is, of course, a generalisation - but that's basically why diesel power is favoured.

Or to put that another way.

One flash and your ash.

Good luck and fair winds.