I'm pondering a project. I have an Aprilia SR 125 Motard, which is effectively a rebadged Piaggio Typhoon. They are identical in all but the stickers and tyres, as far as I can see. I also think the Vespa uses the same engine. I want a bit more speed. I have a full A licence, so am not doing anything illegal here. I also want to keep it stealthy, I don't want it to make a lot of noise or look any different to the standard 125 than is absolutely necessary. I've looked at big bore kits etc, but seems to me I'd be spending half a grand to get another 5 bhp. I realise that's a significant change, but I wondered if there was a better way. I know that Piaggio do have a couple of bigger engines, so I'm wondering if I can just buy a crashed 250 or 300 model, and stick the engine in mine. I'm not a complete moron with mechanical stuff, and have a well equipped garage - I haven't actually done a project like this before, but so long as I don't have to rebuild the engine or get into a lot of cutting and welding, I'm probably OK. A bit of fettling is alright. So, is there a reasonably simple 'yeah, the engine from a ??? will fit', or should I just stop dreaming and get an Xmax? I quite like the idea of having something that looks like a 125, but will take off like a scalded cat when I'm feeling adventurous. Cheers!