Yes I made the gearbox myself after finding out how they worked, I then made a clutch similar to a model car and hooked it all up. The engine is an old Os 40 aero engine which someone gave to me as a non runner with a broken casing and was seized solid, but after stripping it down I just had to clean it out of old castor and replace the bearings and lap the valves in. I had to make my own cooling ring after turning the fins down a few mm and heat shrinking it on, sounds easy but had 5 attempts to getting it right. I knew I wanted it ticking over in the water so had to rig up a pump to give a constant flow, I bought a car windscreen washer pump but that leaked and was too powerful, I found an old model flight box with a fuel pump and now using that, it is linked up to an esc and mixed with throttle channel so the faster you go the more water is pumped. I have not tried the boat as last time out our flying lake was frozen and this week they got a mud run there so hopping for the week after.
The boat itself I had brushless to start with with sound systems and lights but just had no soul, it's been weathered and believe it's been scratch built, some kind of Vosper I think.
Sorry to bomb the thread with videos but could not get any pics on here, hope it will just plod around and sound nice, will get a vid of it running soon.
Steve