The Yamaha RD250 two stroke range of motorcycles has always been popular since the initial release and achieved a cult following when the later water cooled versions were introduced.

The early air cooled RDs are now becoming tax exempt (road find license) within the United Kingdom (UK) due to their age. Every vehicle used on the UK roads requires an annual tax payment based on the type of vehicle. A motorcycle must have been manufactured before January 1st 1979 to qualify to qualify for tax exemption, more details can be found on the official government website https://www.gov.uk/historic-vehicles .

1978 Yamaha RD250

I’ve always been a huge fan of the awesome small Yamaha two stroke motorcycles, like most people of my age I grew up with friends who rode two stroke road bikes. When I started riding motorcycles in the early 1990s, two stroke bikes were fairly cheap when compared to the latest four stroke race replicas and superbikes, for example the Suzuki GSXR750 and Honda Fireblade.

I owned a 1977 RD250 ‘D’ which sported to cast wheels and more integrated seat and tail light arrangement. The engine hadn’t changed much since the introduction in 1973 (some people will disagree!), a simple parallel air cooled layout with reed valve twin carburettors.

The right RD250 to buy

Parts are plentiful for the RD 250 series of motorcycles, therefor it does come down to personal taste if you like the later models over the earlier versions, including the YDS predecessor to the RD range.

You will pay a lot of money for a correctly restored bike, however you will have some confidence the bike will ride and run as it should. Don’t be put-off by ‘points’ ignition systems on the earlier bikes. Digital ignition conversion kits are available for low cost and can be installed by a competent mechanic in an afternoon.

Yamaha RD400
The Yamaha 400 “Big Brother” to the RD250

You also have to remember these machines were built in era which predates modern fuel, which contains additional detergents and fuel substitutes such as ethanol. Fuel systems and metal fuel tanks will stop working and corrode if not maintained and stored correctly. Always factor this in to the purchase, and check with the current own if carburettors have been through an ultrasonic cleaning process and the fuel tank has been coated with a sealer to prevent rust damage.

Something else to note with two stroke motorcycles is “pre-mix” versus use of the oil pump. You will often hear stories of riders preferring to premix fuel with two stroke oil, rather than using the engine controlled oil tank and pump.

Many racers removed the oil tank and pump to mix the exact amount for a race tuned engine. If you are riding a road bike you’ll be much safer keeping the standard oil tank and pump configuration. That time you forget add oil at petrol station will result in a costly engine detonation further down the road!

Happy hunting! I hope you find your dream RD250 and used my article to help you avoid any costly nightmares.

Loading RSS Feed


Leave a Reply

Your email address will not be published. Required fields are marked *