Yamaha RD250 and Yamaha RD350 History
The "Race Developed" Yamaha RD series gained popularity in the early 1970s due to the success of Japanese motorcycles on the racing grounds. Its success started with two almost identical street race bikes - RD250 & RD350. The 1973 Yamaha RD 350 directly evolved from good old Yamaha R5, while Yamaha RD 250 type 352 was a reed valve improved version of Yamaha DS7. There were only few competitors on the market at that time that offered such fast, agile and reliable machines, yet street legal, fuel efficient and easy to maintain.
Reed valve and other specifications
The engine size is one of the main differences between these two bikes as RD250 352 was more targeted to the European and UK market, where 250cc engines were very popular. Both RD250 & RD350 have parallel twin two-stroke air cooled engines, with new reed valve technology and autolube oil injection. The kickstart, like on many early Yamaha motorcycles, is manual and drive is powered by chain. To distinguish them from older motorcycles, they both received an upgrade in the form of reed valves in the intake system (Torque Induction).
By default, both types were fitted by 6 gear transmission. However on some markets, such as Germany or UK, the 6th gear was locked, because local authorities believed that the noise levels were too high. Nevertheless, that didn't stop RD owners unlocking them illegally in an attempt to reach the top speed of 160 km/h.
The frame is again identical to both RDs - slim, rigid street going twin cradle with telescopic forks. The 18-inch wheels that R5 & DS7 had remained, but brakes were upgraded. The front wheel received new disc brakes while the rear wheel retained drum brakes. Most of the other parts are interchangeable and usually match, which can be confirmed by the fact that there was one service manual for both RDs.
Yamaha 350 and Yamaha 250 bike production after 1975
Yamaha RD 250 352 production continued successfully until the late 1970s with several modifications:
1975 - the 6th gear was officially unlocked and exhaust silencers enlarged to compensate.
1976 - New coffin shaped tank and 2 piston calliper disc brakes on both wheels
1977 - New cast spoke rims on both wheels
1978 - Footrests relocated above exhaust pipe, longer silencers and exhaust manifolds, CDI ignition & improvement to brake callipers
1980 - Liquid cooled RD250LC introduced
The classic RD 350 ceased production in year 1976 to make space for larger and more powerful street race bikes RD400. But not for long, with introduction of Liquid cooling in 1980, RD350LC returned followed by RD350 YPVS in 1983.
Today RD Series motorcycles are in a modification boom, with garage enthusiasts turning these vintage legends into RD350 café trackers, RD350 Choppers, Bobbers, even Drag Bikes and other custom projects. To find an original untouched RD is almost impossible. This is partially caused by several factors. These powerful machines usually endured several accidents during their lifetime and therefore undergone numerous repairs, but also custom-builds were very popular even in the early days. Having your street racer customised to suit your style was as popular in the 70s as it is still today.
1973-75 Yamaha RD250 parts and RD350 spares
Air Cleaner Parts
If your motorcycle loses power, it is usually a sign of an intake issue. We stock most of the essential rubber items for air box repair such as air box dampers, air box grommets, air box strap, carb. manifolds and well as intake Y boot joint with matching clamps.
Stand, Footrest & Brake Pedal Parts
If exposed to element, footrest rubbers crack, we therefore stock front & rear footrest rubbers, gear lever as well as kickstart rubber. We also have footrest dampers, stand stopper, tension spring and various nuts and bolts in stock.
Crankcase & Transmission Parts
If you need to rebuild your crankcase, you should not opt out for cheap oil seals. We supply ARS Japan OEM original crank seal kit. Add new gaskets or breather and your restoration is set for success. If you need new absorbers for your Cylinder, you don't need to go far either, we have a full set of RD250 & RD350 cylinder dampers in stock.
Oil Pump & Tank Parts
Rebuilding an old oil pump is certainly easier than finding a new one on the market. Through we don’t supply hardware for it, we have a full kit of seals and gasket to help you restore your classic Yamaha lube pump in no time. We also stock replacement oil tank windows, dampers, pipe holders or even blanking plugs if you decide to remove the pump altogether.
Plastic Parts & others
Besides all the rubber items, we now added some perishable plastic parts such as rear light lens covers, indicator lens covers, oil tank fins and reflectors. We have bulbs and oil seals, paper gaskets, cables and many more.
The majority of these parts have been discontinued for decades! We don’t aim to provide a complete list of spare parts, but if you can’t find a specific part on our website to fit your restoration project, or you need a parts list, please contact us via email address or the contact-us form below. We also offer free shipping on orders over certain value.
We now have over one hundred RD250 parts & Yamaha RD 350 parts now in stock and keep adding more. If you can’t find the part you are looking for, please email us as we will do our best to source it out.
Models & VIN Numbers
1973 Yamaha RD250 - 352-1XXXXX - Butterfly Blue
1973 Yamaha RD350 - 351-1XXXXX - Brandy Red
1974 Yamaha RD250 a - 352-2XXXXX - Amber Brown
1974 Yamaha RD350 a - 351-2XXXXX - Ruby Red
1975 Yamaha RD250 b - 352-3XXXXX - Clean White
1975 Yamaha RD350 b - 351-3XXXXX - Portuguese Orange
Technical Specifications of Yamaha RD250 & Yamaha RD350
|Model:||Yamaha RD250, RD250a, RD250B & Yamaha RD350, RD350A, RD350B|
|Motorcycle Type:||Street Sport|
|Dry weight:||144 kg|
|Ground clearance:||150 mm (5.9 inches)|
|Fuel tank size:||16 litres|
|Displacement:||247 cc (RD250) or 347cc (RD350)|
|Engine:||Twin, two-stroke, 7-port Torque Induction engine|
|Top speed:||150-160 km/h|
|Fuel system:||Two Mikuni Carbs|
|Fuel control:||Port control|
|Cooling system:||Air cooled|
|Exhaust system:||Twin chrome|
|Frame type:||Steel tube|
|Front suspension:||Telescopic forks|
|Rear suspension:||Dual shocks|
|Front brakes:||Single disc brake|
|Rear brakes:||Drum brake|
If you require 1973-75 Yamaha RD 350 parts diagram or Yamaha RD 250 parts list, please contact us.
For further information about Yamaha RD models and their history visit the cycle magazine - The Cycle World.
The road test review can be found on Classic Motorbikes.
Also, you can get lots of good advice and help from fellow motorcycle enthusiasts on the Aircooled RD Forum