Hi Pilot
"Hobby Hangar" at Yeovil should sell bits for your engine (or supply a replacement when necessary). The OS 40 is a good reliable engine which, in a fast scale boat, should give years of good service.
The output is about 1 kw (approx 1.4 bhp).
You will need silicone tube from the water inlet (under the boat) to the engine and from the engine to the outlet. If you use a tuned pipe (unnecessary with this type of boat) you would also need silicone tube to and from that.
You will also need (smaller bore) tube from the fuel tank via a filter to the carburettor.
Ideally, the engine should be mounted on rubber 'bobbins' and use a flexible coupling to minimise noise output (you want to keep using your lake!!) and you will need a silencer (altough an aircraft type with silicone outlet would be sufficient).
If you are within range of Bristol, a chap called Bernard Holder (contact details on
www.bmprs.co.uk 'sales and wants' section) would be happy to assist you, I'm sure.
Cheers
Danny
BMPRS Chairman