He took the thing right down to the frame, replaced lots of engine bits and put the bike back to more or less stock shape. There remained a pretty wild Stan Stephens porting job, a pair of Allspeed spannies and upgraded suspension, the rear shock being a particular weak spot on the RD350, but all the stock ones would’ve been discarded by now.
In this state, with flat bars, a converted Corbin seat and rear-sets, the RD was comfortable, fast to the tune of 125mph and reliable for about 10000 miles at a time. After that kind of mileage the bores were knackered, the clutch plates warped (all those wheelies) and the mono-shock linkages shot. The only way to keep an aged RD running on the cheap was to have plenty of spares and a bit of workshop skill. Even then there was nothing that could be done about the 30 to 35mpg fuel consumption.
There was no way of knowing how many miles the RD had done when it came into my hands two years ago. Better not think about it, as six figures were involved. The motor had just been rebuilt but was running poorly. The last one had seized when a reed valve shattered and bits were drawn into the bore. Some of the pattern reeds are dubious and it’s best to stick with stock items.
The engine started and ticked over easily but stuttered from 2000 revs until a violent amount of power came in at 6000rpm. Forced as I was to take off with a massive handful of throttle, wheelies were the order of the day. Transmission looseness made subsequent gearchanges rather hit and miss (as in being hit by cars suddenly confronted by a bike wailing at 12000 revs in a false neutral and missing out on lane changes, lights and overtaking manoeuvres).
After spending loads of dosh on different grades of spark plug, sealing the exhaust joints and playing with different carb jets I decided that the carbs were at fault. My local Yamaha dealer kindly informed me that they were one of the first set ever made for the LC, therefore not exactly brilliant even when brand new. Finding a better set proved traumatic until I handed over fifty quid for a pair of late LC carbs off a crashed bike that had only done 33000 miles.
After a bit of playing around with carb jets I had an engine that ran relatively cleanly at all revs. I say relatively as some induction mismatch combined with transmission lurch provoked surges at 3000 to 5000 revs and the feeling that the carb was connected to the throttle by a couple of miles of knicker elastic. The violent explosion of power still occurred at 6000 revs, all the more disconcerting because I was never quite sure when it was going to pounce.
The chassis, in contrast, was well sorted but given a hard time. I couldn't fault the way it held a line, could be heeled over easily or braked on the racing Brembo calipers out front. New bushes, heavy-duty springs and a fork brace had the front end well sorted - better than new, in fact! I’ve never come across a bike that felt so controlled when on one wheel or with the back tyre under wheelspin. I must’ve looked a real hero when showing off.
Unfortunately all this violence had an effect on the consumables. Amongst these I must include frame, monoshock and wheel bearings - anything from 4000 to 12000 miles; they lasted to a rhyme all of their own making, though I never bought OE components. Tyres never lasted for more than 6000 miles, though why the Metz front didn’t do more defeats me as it spent half the time off the tarmac - must've been all those stoppies. Cheap chains lasted all of 3000 miles!
Expense, expense, expense... but I bought the bike dead cheap and this level of fun, extracted from some big four, would prove even more wallet shattering. As well as hurtling through London on one wheel, the bike proved able to hold 90mph on the open road. It would go faster, but its naked nature meant my arms started screaming at such abuse and my neck was almost broken by the wind buffeting.
Considering that the frame had been bent and straightened at least twice, stability was brilliant, the bike even being resistant to heavy side-winds. The 350lbs of metal would only become upset when we hit a series of bumps at speed. The whole bike rattled as the stiff suspension tried to sort itself out - the softer ride produced by the OE equipment might have helped, but I preferred the secure, sporting feel of my setup. There was extra frame bracing, a leftover from its racing days and undoubtedly the reason it felt so good.
A stock bike, especially after 10000 miles of abuse had got to the suspension, could be a bit of a speed wobbler, there being so little mass to damp out the weaves. On my bike I often burnt off much faster machines through the corners as I didn’t have any problems with the stands digging in they'd been removed a long time ago.
My bike only became dangerous when any of the bearings went. The bars fluttered in my hands or the wheels felt like they were falling out. Once, I ended up stranded about ten miles from home with both wheel bearings shot. I don't think the front appreciated the way the wheel was hammered down on the tarmac when I had to abort a wheelie session. The wobble home took two hours and left me with traumatised wrists.
One of the disadvantages of hobbling along at 5mph was that it gave the peds a chance to complain about the noise and emissions. These were always present but I never thought that the chortling at low revs was annoying but could appreciate that the screaming at 9000 revs might turn a few heads! A worn oil pump contributed to the density of the cloud that followed the bike. Startups could be especially spectacular even on ‘smoke-free’ oil.
The chassis was taken apart so frequently that it didn’t suffer from the common problem of seized in bolts or spindles. You have to watch out for rust on the engine bolts, though, as they can snap if corrosion gets a hold. I think it’s the combination of buzzing and rust that gets to them, once their fit in the engine becomes a little loose the whole engine shuffles around. It's easy enough to suss this because the petrol tank splits up from the vibes. A burnt out groin often results - a real fun machine, but this was one aspect that I didn’t experience.
One other aspect of the vibration was the ease with which the exhaust could crack up. It’s lucky I’m handy with a welding torch. I ended up with a revised mounting system, a big wedge of rubber bonded to the exhaust stay which let the silencer move with the engine rather than fight against it. Allspeeds last for about five years before the chrome does a runner if you ignore the baffling burning out (and, why not?).
I didn’t crash very heavily on the RD, perhaps because cagers always knew I was coming. I kept the appearance up with a weekly clean-up - also necessary so that I could check the frame for cracks, a not unknown calamity on aged LCs. The popularity of both the 250 and 350 models meant there were loads of bits available, plus plenty of racing stuff for those who need to get serious.
After two years and around 18000 miles I'm still impressed despite all the hassles and expense. The engine’s about due for a serious rebuild but I've already bought a rebuilt crankshaft, race pistons and barrels, new gaskets, etc. I’ve almost enough bits to build a second engine, only the complexities of the gearbox puts me off. Used stuff is very variable, from rotted stockers to hot race replicas.
They aren't for the mechanically ignorant but for cheap kicks and speed they’re very hard to beat.
Buy one if you have the chance.
Dave Grays