Fire and the fury came to mind as I topped the ton for the first time on the RD250E; indeed, for the first time in my life. The frenzy of vibes through the rear-sets added to the feeling of fighting the elements, as did my body wrapped around the tank and head in the clocks. A pain ran through my neck as I craned upwards to see where I was going, although the howling gale took the usual pressure off my wrists, resultant from the clip-ons.
The RD was basically stock, save for some minor carb mods to suit the expansion chambers. This emphasized the way power suddenly flowed in at 6000rpm, although the reed valve motor still produced a reasonable amount of torque for trawling through town in a tallish gear, something necessary to avoid the attentions of the police who did not appear amused by the snarl of the spannies beyond six grand.
The chassis was also mostly stock. The big change was to the riding position which helped put more mass over the front end, curing most of the insane mono-wheeling that afflicts the stock RD. I'm not against wheelies, as such, but can live without the front wheel leaving the tarmac when accelerating out of bends.
Handling at the ton was surprisingly stable, although it was a smooth, straight bit of motorway. The bike could be thrown way off line on rough country roads, more, I think, down to its low weight than any chassis defect, although the front end always threatened to go light under serious abuse. There was a slight weave from the back tyre, despite the flash alloy swinging arm I'd fitted but it did not worry me.
102mph on the clock was the most I could extract from the wailing stroker twin. Not bad going for a bike that had led a most varied life. The previous owner, a friend, had bought it in a pretty decrepit state for £125. The engine was out of another bike, although what was left of the old one was still around for spares. The chassis was refurbished during the 18 months he owned the RD, before selling it to me for 650 quid, in fine fettle but a totally indeterminate number of miles under its wheels.
I'd had the bike for five weeks before I'd become sufficiently sure of its characteristics to do an early morning high speed run. I was easily won over by the ease with which the RD could be flicked through curves and sped through town, speed always necessary to make sense of the cafe-racer riding position.
I was therefore a bit miffed to have my joy at cracking the ton ruined by the realisation, as I backed off to more legal speeds, that the gearbox was stuck in top! The forty mile ride back in such a tall gear ruined my peace of mind for the rest of the weekend and, more importantly, also burnt out the RD's clutch plates. Waves of heat were coming off the engine by the time I pulled up at the previous owner's house - he knowing a lot more about RD's than myself.
He's a good chap, had the crankcases split in a time so short I would still have been trying to get the petrol tube off the carbs. He had done it so often it was second nature to him. I never did quite understand the cause of the problem but it was resolved by using some bits out of the old engine, as was the clutch. In a blur of hands the mill was reassembled and put back in the frame. The whole operation had taken less than 2 hours!
The gearbox and clutch were working again, so I was able to ride home in a less despondent mood. A month went by with a lot of joy, a few near misses when I became overconfident and a set of Pirelli tyres going down to the carcass. They had never really impressed me even when legal, when bald they allowed the chassis into some most disturbing behaviour, that once had me pulling over to throw up my breakfast.
My friend reckoned a set of Avon Roadrunners would be better, and they were. The Yamaha felt much less twitchy and less susceptible to white lines and the like. My confidence in the bend swinging abilities of the little RD grew by leaps and bounds, surprising myself by giving some real hard cases on bigger machines a run for their money. The RD250 can be a real giant killer!
The bike began running very strangely. It felt like the carbs were way out of balance or as if there was a spark plug dying. The two cylinders appeared to be suddenly working against rather than with each other. A real struggle ensued trying to crack a mere 80mph, the engine vibrating like the main bearings were on the way out.
Fearfully, I consulted my friend. It was either something very serious and expensive or the carb slides were worn out. He let me borrow a set of refurbished carbs which made the Yamaha go like a bat out of hell. After some bargaining fifty notes changed hands and I was back in business.
Another three months went by, much more in pleasure than in pain, when I noticed that oil was being consumed at an even more voracious rate than normal. If I wanted to do a 300 mile run I had to strap a five litre can to the back of the seat. There had always been a bit of a smokescreen but now it was becoming a bit absurd. A couple of minutes idling at a junction meant the immediate vicinity looked like a dense fog was closing in.
My mate diagnosed main bearing seals on the way out. A not uncommon problem on hard ridden RD250s. So common, in fact, that he earned a reasonable income reconditioning cranks, so I was lucky to fix the problem for only 60 notes. However, the rebuilt engine never displayed the zest of the old one and I was aware of a lot more intrusive vibration.
I rode the bike for six months, but in a relatively mild and sane fashion, mostly for getting to work and the odd weekend thrash with my mates. Did almost 9000 miles with nothing more than spark plugs, oil and drive chain (pathetically short-lived) replaced.
Somehow, I'd outgrown the delights of the stroker. Riding became more tedious than pleasure filled. Having a friend turned into a vegetable when his RD350 engine locked up solid did not help any. The chassis was showing signs of needing serious money spent with a bit of looseness in the bearings and the Roadrunners about to turn very illegal. When some vague acquaintance decided he was desperate to get in with the RD crowd I did little to dissuade him from handing over £750.
Overall, it had not been a bad experience. Strokers can delight with the way they lay down the power, but they also irritate with their quick wear components and lack of civilisation. Worth experiencing but not repeating.
Rollo
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A mild cafe racer in immaculate condition. The DX model fitted with electronic ignition. Clip-ons, rear-sets and a single racing seat with a large bum-stop. That would have to go, but he threw in the stock saddle as part of the deal. I bought the ten year old machine in 1989 for £500. Some might consider this a lot for an old two stroke twin but it was one of those machines that shone with tender loving care.
The reed valve motor was stock, still able to run cleanly below 6000rpm. Or that was what I thought at first. I found that more than ten minutes of town work choked up the engine. It sulked until a burst of acceleration was applied. A large pulse of power that was surprising for a bike of this era. I could see how it would become addictive. As the engine cleared itself out, a large dose of smoke out of the exhaust added to the pollution levels. The separate oil tank and pump combined to leave just a hint of smoke during normal running, although it would come back intensified on the overrun.
The first time I rode in the dark I thought the headlamp was on the pilot setting. No, the yellow patch up ahead was the product of the main beam. It was good for no more than 25mph on my favourite country lanes. Silly, silly, silly, I thought, as I rode off the road at 45mph. Bump and grind over some grass, a bit of samba dancing when the tyres lost their grip and a soft landing on the damp earth.
We both survived with our frames intact. I rewired the lamp, put a more powerful bulb in and charged the battery. Made sod all difference, the reflector must've been of a very poor design. Wandering around the breaker's I found something better.Good for 50 to 60mph on unlit roads.
That wasn't the end of the electrical hassles, the kill-switch decided to short out intermittently. I'd come out in the morning having no idea whether or not the engine would start. If it hadn't roared into life by the fifth kick I knew it wasn't going to start that day. I got on to the problem after I thumped the bars in frustration and the motor had started first kick after that. Eliminating the switch was the cheapest, if slightly dangerous, solution. Starting also became impossible if the spark plugs weren't changed every 1000 miles. I didn't realise this, almost ended up in a truss after abusing the kickstart for a whole morning.
Great care had to be taken when changing plugs. It's such a frequent job that the threads become very weak, dead easy to strip if too much pressure was applied or cross-thread them. I always put a bit of grease on the new plug to help it home and ensure it didn't corrode in. The cylinder heads were laughably easy to pull off, so it wasn't the end of world if a helicoil job became necessary. I did a decoke every 5000 miles, the silencers needing much more attention than the top end.
There was a bit of rust on the undersides of the silencers, the seam starting to crack on one side. When at the motorcycle show I spied a shiny set of Microns and a jet kit I couldn’t resist. The silencers needed some spacers and the jets were incredibly difficult to remove from the carbs but a weekend's work had the RD250 back on the road. What a noise she made. Neighbourhood dogs howled in protest and the wife starting gesticulating madly. I was already in her bad books just by owning a motorcycle, now......
The Microns moved the power up the band to 7000rpm, where the tacho needle flicked around to nine grand before running out of enraged steam. It would've been tremendous fun had not the tinny wail reverberated around inside my full-face helmet. After a few minutes I had such a bad headache I could barely see. Back home I dismembered the old silencers, hammered and welded the baffles into the Microns. I had to put the old jets back in the carbs but apart from a slight hesitation around 5000rpm I was quite pleased. More power than stock, less noise than the Microns. I later learnt that I had bought race rather than road pipes.
Top speed was 95mph, although I once did the ton down a long downhill section, accompanied by fierce vibes through the footrests. Fuel varied between 40 and 50mpg, depending on throttle abuse. The suspension had been tightened up, the tubular frame was very strong, the overall effect of a nicely stable bike that was also dead easy to throw about, whether at town or open road speeds. After all, Yamaha used a lot of their race track experience in the design of these machines.
It was a pity they didn't learn how to make components last a long time. Perhaps it wasn't a problem in Japan, but in the UK chrome and paint were badly affected. The past owner told me he’d had the frame resprayed and replaced most of the cycle parts with new OE items, so old age was certainly not an excuse for their poor longevity. The front mudguard rustled so badly, and so rapidly, that it ended up rattling on the tyre. A plastic replacement and fork brace were added. Before I sussed that the back guard was going the same way, the light bracket fell off, tearing out a large clump of wiring.
The first I knew of it was when the cops pulled me over. They were not amused at the lack of light and numberplate. They vented their anger on the seat, which pulled off and promptly fell apart from corrosion fatigue. Only fervent protests stopped them kicking the guard to dust. I was booked for riding a machine in a dangerous condition, no numberplate and lights, and told to take all my documents to the local cop shop. More plastic replacements.
I could hardly replace the frame with plastic tubing, the way the paint peeled off in favour of rust was astonishing. I've never come across something that rusted so rapidly. I slapped on some Cure-Rust, metal oxide paint and a final layer of Hammerite, which seemed to hold it at bay. Within six months of purchasing an immaculate machine it had gone back to the state of a ten year old dog, but after much painting, replacements and praying it was back in good shape.
After the winter of discontent came the summer of incredible heat. I couldn't keep off the Yamaha. A brilliant time but the high temperatures showed up a problem in heavy traffic. The engine was overheating, huge gusts of oily heat coming off the motor. The underside of the petrol tank was dangerously hot, giving me visions of my private thingies going up in flames. A hotter grade of plugs and better quality oil helped a little. By the time the clutch was dragging, like it was locked up solid, I knew it was time to let the engine cool down for thirty minutes.
One solution was to ride between the cars at an indecent clip. It was quite easy to wheelie the RD in first or second, even with the clip-ons. It wasn't something that I did very often, though, the clutch always felt like it was going to explode for a few miles afterwards. The front disc was always adequate for such cut and thrust madness but a few high speed stops would get it hot enough to fry eggs. I found this out when I poked the disc one time. Ouch!
For an old 250, I was pretty pleased with the way it'd cruise along at 85mph, helped by the clip-ons and rear-sets, until I worked out that it was returning 35mpg. Anything over 80mph meant that fuel frugality took a massive dive. A constant 70mph gave an acceptable 50mpg, but those revs, in top gear, coincided with a patch of annoying vibration that rattled my feet. At 65 or 75mph it was dramatically smoother.
The Roadrunners lasted near on 10,000 miles before the handling became a little odd. The chassis would fall into corners and wobble at about 80mph. White-lines would throw the front wheel around. Damp roads had to be approached with caution. These horrors turned up as soon as the tyres hit the 2mm mark. A new set soon had the handling back up to standard, although they needed a good 300 miles before they were properly scrubbed in.
Come its second winter in my hands, the carburation went to pot again, some very erratic running made it a bugger in town. The clock had 33000 miles on it by then, so I feared that it was rebore time, although once in the power band it'd still whizz off up the road. Took the carbs off to have a play, noticed that the reed valves were deeply pitted. I knew someone who fitted some racing reeds only to have them break up and subsequently wreck his engine. That ensured that I bought a new Yamaha set.
Overall, the Yamaha was proving to be a reliable means of transport that didn't need much money spent on it. It never failed to get me to work on time, usually with a singing heart and big grin. It was in nice shape after all the work I put into the chassis and unlike most four stroke 250s I never became bored riding it. I could also keep up with friends on middleweight fours on most roads except motorways. I rather thought its lack of outright speed was good, it made sure I never lost my licence unlike two friends (105 and 117mph....). The affair came to a sad end one morning. I came out of the house all togged up only to find an empty space instead of the RD. Some rotter had half-inched her!
M.H.