What to buy and how much to pay

No decent RD400 is going to be cheap so if you see one going for pocket money be wary. It’s easy to buy a mix-and-match monster with all the wrong the parts on it, so unless you can see genuine evidence of the bike’s history and build get expert input. The Achilles heel of all the RD250/350/400 twins is that so much is readily swapped around, over and across. Therefore it’s extremely easy to buy a hybridised RD400 and not even know it. There are a lot of American market imports for sale out there and there’s no justified reason not to consider one. However, remember that the USA market models are aesthetically and physically dissimilar to the UK models – always running different paint schemes/decals and generally running a smaller tank. The C models were offered with alloy wheels as an option but many have been retro converted anyway, making a UK spoked wheeled C model something of a rarity now. There was and is a raft of contemporary and modern running parts out there but not everything is automatically compatible per se. Many 400s now suffer from fuelling issues due to flat spots; SPA Motorcycles of Cheltenham offers a bespoke carburettor service that sorts out these issues beautifully. Prices for RD400S are on the rise and have been for years, nothing viable is cheap! Reckon on £2500-£3000 for even a basket case, £4500£5000 for a decent used runner and anywhere from £7500 to £8500 for a top notch example either restored or original. In the last few years the RD400 has almost doubled in money and is hitting similar values to the RD350LC!