Classic Motorcycle Mechanics

YAMAHA RD350

Scoop Mots his two-stroke twin.

- cmm

If there’s one thing about old motorcycle­s that continues to impress it’s the very obvious fact that every day has the potential to be a school day. When the back wheel was out previously I’d removed the shocks and had a good push/twist/pull and it all felt good. Knowing there was no obvious play in the swingarm didn’t necessaril­y mean that the old bushes were well greased so I called my newly acquired Sealey grease gun into action: which strangely didn’t fit. Yamahas of this period run parallel bodies, ball topped, grease nipples which allegedly were used for swift greasing on the production floor. Apparently they save millisecon­ds getting the gun on and off. Not wishing to spend 40 notes on a set of fancy grease gun fittings I blew a whole £2.50 on ebay for convention­al nipples that used the same threads. Firing in the grease with the new fitting saw their older counterpar­ts exhibiting age-related incontinen­ce; the internal springs must

have died. As I say you never stop learning just because you work on old bikes! Last but by no means least the oil tank was topped up. If you remember the original images of the RD350 there was two-stroke oil all over the guard. The siting of the cap is less than ideal so each and every time the tank is filled I break a rag out. It’s a foible of the RD’S design that makes a simple job frustratin­g and given how cramped it all is under the seat it makes you wonder what was wrong with the older layouts where the filler neck was actually accessible! Well the RD350 made it to the MOT station under its own steam and here it is looking rather glamourous on the bench at Flitwick Motorcycle­s, main Yamaha dealers. Amazingly, they consistent­ly put up with me and my old tat while servicing stuff like modern R1s and R6s. I’m never really sure whether the team there are really just humouring me in the hope that I’ll one day buy a new Yamaha and thereby put some real money across the counter I’ve been leaning on for more than two decades. Of course classics being classics there was some pre-mot drama two days before when a quick sanity check saw precious Aspen 4 lead-free, ethanol-free, fuel dribble out of the fuel tap. I’d previously said something on the tank would bite me and it did! For reasons I still cannot fathom the actual tap lever had gone as floppy as a sock and the culprit turned out to be the wave washer that bears down on the lever’s outer face. All the more galling is the fact that just before fitting the tank I’d replaced the abused old 3mm Philips screws with some larger headed Pozi-type ones that actually gave a better seal. After a severe talking to, the wave washer agreed to play ball but suitable spares are being acquired as I write. That first ride to the MOT station can be something of a worry; is everything

tightened correctly, is the oil pump working okay, how long will it take the brakes to bed in etc? Of course if the job is done correctly then everything should be hunky dory but I always leave way too early just in case anything needs adjustment and for once it did. Once warm, the tick-over needed a little bit of fettling so a quiet country lane saw a would-be/once-was teenager fettle an RD350 by the side of the road just like he used to more than 40 years ago. Happy that all was good the maiden voyage proceeded without incident and an-mot was duly acquired. Even better the local post office was happy to issue an ‘historic vehicle’ road fund licence (still miss my tax discs though!) and send it off the V5C for updating. Ten days later the RD had officially acquired pensioner status. The icing on the day was finding the local locksmiths in Flitwick were able to cut me a spare key for less than a fiver. D&G Locksmiths; you are stars! Carefree, road legal and with smoke being made the return journey was simply joyous. The bike pulled well, made the right sounds and ran like they always did. What surprised me was just how flighty the front end could be in the lower gears if you forgot yourself and gave it a handful. Thank God my increased mass since 1975 has some uses! Progress up to illegal speeds was just as rapid as I recalled and the famous torque bestowed by the reed-valves was evident but perhaps not as all-encompassi­ng as I remembered it to be. Flat spots would be too harsh a descriptio­n and it certainly wasn’t hesitancy. I have plans for this which revolved around the jetting changes we made some time ago and my mate Rob is on standby with subtly different nozzles and jets; it’s not far off but there’s still room for improvemen­t. There’s also a crafty dodge to be carried out with the airbox which recently featured on our workshop pages. And talking of improvemen­ts the front brake needs to up its game. The totally rebuilt system works okay and stops the bike but it’s not as sharp as I know they can be. The issue here is that the new pads need to bed in on the old disc and this takes time especially given the slightly dubious set-up here. Yamaha installed anti-chatter shims on these RDS and the pads indubitabl­y do not chatter. But… the shim is only a semi-circle of stainless steel between brake piston and brake pad; this means the latter is pushed out at a shallow but significan­t angle. It won’t be until the all the friction material makes uniform contact that maximum braking will be attained. On the plus side the witness mark is getting wider with each ride, so it’s heading in the right direction. Sadly one thing that isn’t is the rear suspension. There’s no point judging an early 1970s bike by modern standards but the rear shockers are simply dire. Honest! Oversprung and underdampe­d, they really are not up to the job and I’ll need something substantia­lly better if I’m to exploit the RD’S legendary handling. Oh yes, Project RD350 is far from being finished!

 ??  ?? The warhorse gets an MOT.
The warhorse gets an MOT.
 ??  ?? Ahhhh the fuel tap!
Ahhhh the fuel tap!
 ??  ?? Oil gets filled.
Oil gets filled.
 ??  ?? Brakes are bedding in.
Brakes are bedding in.
 ??  ??
 ??  ?? Sealey grease gun goes to work!
Sealey grease gun goes to work!
 ??  ??
 ??  ?? That oozing can’t be good!
That oozing can’t be good!

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