Outboards running on LPG

[Diesel]

Anyone have any thoughts on Running an outboard on LPG?
We are doing some conversions at the minute at work so you can have cheap fuel. Only for four strokes at the minute.
We are doing to 200 hour trial with our 115hp Mariner and so far so good. We have also done a 15hp but there all quicte simular systems so we can do it to any Merc/ Mariner 4 stroke.

The smaller engines are really aimed at river boats that already have Lpg on board for cooking etc as you can run them off an orange gas bottle where as the bigger engines have to have bigger tanks to stop the gas from getting to cold.

[Dirk Diggler]

I believe the harbour master on the Hamble tried it with a couple of Honda's, and either Calor or Shell had a Mercury converted on display at the LBS a few years ago.

But why bother, the latest versions of 4 stroke outboards sip fuel so why jeopardise your warranty? And why would anyone want to spend money on converting a 15hp?

[Jonny Fuller]

I think Mr Pascoe of MPL Sportribs is the recognised world expert on LPG conversions for OB's, they only rendered about 10 engines 'basket cases' up in Windemere back in about 96!
They were trying to get 2.5 efi's to run on it for a new LPG powered world water speed record, but of course they wanted them to run 'flat out' for 2 kilometres.
They rarely made the 1st pass without freezing the evaporator unit, losing gas supply, running lean as a result and going pop.
When they ran out of motors, and were also running out of Windemere week, they organised a crate of engines to be airfreighted from one of their US based OB dealer/tuners (owned by their team owner) When the crate arrived, flown overnight to heathrow, then helicoptered up to Windemere, all at enormous cost, to Marks horror the crate contained three blown engines that they had shipped over to the US the previous week for re-building! OOooops.

[Diesel]

Our engines will be covered under the warranty!, The smaller engines are really for river/canal use as its difficult to buy petrol on rivers other than taking your fuel cans out of the boat and taking them to a petrol station.
As form the bigger engines freezing up thats not a problem either, the gas is injected directly into the top of the cylinder rather than in the manifold so no popping back, they dont freeze because we use a proper size evaporater unit. the tank on our boat is a 100ltr stainless steel tank. The engine will run flat out for as long as you want.
Its aimed at people who use there engines commercially eg river police etc, who put anything upto 100hrs a week on there engines. Not really for leisure users. The boat we are going to be using as a demo boat is a 5.85m Ribcraft which has had the gas tank fitted inside the center seats and a Mariner 115efi 4 stroke.

[Dirk Diggler]

Originally posted by Diesel
Our engines will be covered under the warranty!,

Are you saying that Barrus have given their approval for this conversion and will honour the warranty in the event of a mech failure?

Or are you giving your own warranty?

[Diesel]

Yeah we are giving a warrnaty (Barrus) as we have done the conversion.
Not sure the in's and outs's of it yet though. The engines still have some trials to be done yet.

[Rogue Wave]

Anything that gives less wear on the envoirenment and provides cheaper boating should be supported . I hope ir works out. The harbour master in Hamble did have a launch running two Mariners 4 strokes i think they were 90's not sure. this was about 3 to 4 years ago

[Jono Garton]

Originally posted by Rogue Wave
The harbour master in Hamble did have a launch running two Mariners 4 strokes i think they were 90's not sure.

hope they run better on gas than unleaded