If like me you enjoy building larger models then you might like the offer that Tesco have at the moment for a 25cc strimmer for £39.99.
Strimmers are great donors for model boat engines as they are the right size / shape, can be inclined on engine mounts, have built in auto clutches and even have long flexible drive shafts.
Its such amazing value that I have ordered four just to strip and put into store.
Paul (enjoying the credit crunch)