Yamaha RD400

I blamed the UMG. It was they who suggested that the RD400 should wheelie on the throttle. The owner was beside himself with rage after watching me scream up his street on the back wheel. Okay, the clutch was rattling a bit and we were both coughing from the pollutants. The latter his fault for using cheap stroker oil. He waved me away, telling me the next time he saw me it would be his fist that I saw first. He was only a little chap but I resisted the temptation to pat him on his head.

I got out sixteen fifties and waved them under his nose. Quite comical to watch him leaping up and down trying to reach the dosh. Some people! Ten minutes later I had the doc's and the RD in my possession. I left on one wheel and dumped a layer of pollutants over him, just to let him know who'd won out.

I'd always fancied these old stroker twins. The bike was basically a stocker, just Koni shocks, modern Metz's and flat bars. The most surprising thing about the motor was how easy it was to ride. Expecting all the power at the top of the rev range I was shocked to find loads of midrange torque. By 10,000 revs all the power the engine was going to deliver had arrived, no point trying to seize the aircooled mill.

The bike was also surprisingly smooth, thanks to the rubber mounted engine. It was close to electric in its delivery. Only took 300 miles for some roughness to intrude. Panic subsided when I realised it was only the carbs out of balance. My E model had electronic ignition, so all I had to do was the carbs and keep an eye on the gearbox and oil tank levels. Turned out the carbs needed a balance every 700, or so, miles. Not brilliant but I couldn't really complain.

Handling was pretty good. Easy to fling through the bends, stable in a straight line, I only felt a little at a loss when up on one wheel. The bike felt like it wanted to flop sideways if I didn't concentrate on maintaining the balance point. It was even possible to get the thing to loop the loop if I ever went really wild on the throttle and the clutch - scraping the numberplate woke up the ped's and had one cop car trying to run me off the road. I did pull over, eventually, had a couple of uniformed clowns leaping up and down in a frenzy of hatred and mean-mindedness.

This was pretty good going for a machine almost twenty years old. The clock only read 28000 miles, but I had no clear idea of its history - the erstwhile owner wasn't very talkative after my testing antics. I did feed it on decent, smoke-free stroker oil which got rid of the MZ-like clouds of pollutants. The Yamaha had a fairly advanced oiling system, with a separate tank and metered oil pump.

No, I had much more hassle from the disc brakes. They were attached to cast alloy wheels that weighed half a ton each. That wasn't the problem, though. The calipers lacked both smoothness and preciseness, never possible to really know what the brakes were doing. They grabbed on, groaned and went AWOL when there was a little rain on the agenda. Occasionally, they would suddenly work with a viciousness that locked the wheel and tried to skid the bike off the road. Frightened the stuffing out of me, the first few times it happened.

I couldn't go on like that, given the unpredictable nature of the weather. Taking the calipers apart was the usual round of fun and games. Heavily scored and worn pistons were the main nastiness. Doing the rounds with the dealers and breakers was another bout of fun and games. MCN's classified's eventually turned up someone specialising in RD's. After reassembling the brakes with new pistons, seals and EBC's I was expecting a massive transformation.

If anything, the brakes were even worse, with hardly any retardation. Luckily, this was just the pads needing to lose their glaze. Ten miles later, the brakes were both more powerful and more predictable. Wet weather work still needed some care, feathering the levers to keep the water off. It would still whack on without any warning if I didn't do that.

A gentle hand of the throttle was also needed in the wet. Otherwise, the back tyre would skid alarmingly. Overall, it wasn't the best of bikes to ride on damp roads, speed had to be kept down and it never lost a certain feeling of edginess. Poor weather also brought out a lot of alloy corrosion, and the odd bit of chrome seeped rust. The paint, in contrast, though faded never gave into the weather. The only other problem, in the wet, was that sometimes the engine would cut out on to one cylinder, especially if the spark plugs hadn't been changed for 500 miles.

The electrics proved quite nasty about 6000 miles into my ownership. The battery went dead overnight, then the bulbs started to blow and even a 50 amp fuse was burnt to a cinder. All these problems were eventually traced to a rectifier that wasn't working properly at high voltages - difficult to diagnose as it was fine at tickover! The ubiquitous Superdream item was wired in but promptly went up in flames. Yes, the generator was burnt out!

A full electrical refurbishment added up to more than I wanted to spend on the bike. I kept charging the battery up overnight. Good for about fifty miles as long as I used hand signals rather than the indicators and forgot about such sophistication as working lights and horn. Starting was always the mildest of kicks, a rare day when it didn't rumble into life at the first attempt.

A few months later I bought a seized RD400F for £200. The chassis was quite shabby but the electrics were fine. My bike was upgraded and the seized one stripped down to its component parts. I managed to sell off the rusty chassis bits to an enthusiast for £125 and most of the gearbox parts for £60. Still have the frame with logbook to get shot of, should come out ahead of the game.

Despite being a nasty stroker, I quite often got more than 50mpg out of it - just keep below 7000rpm. 35mpg resulted during flat out blasting but as that involved riding at 110-115mph everywhere it didn't happen too often. Chains and tyres were given an easy life by the stroker power pulses, never needed replacing in 9000 miles of fun and games - they weren't new when I bought the bike!

Overall, a surprisingly sophisticated and versatile machine that gives the lie to the idea of strokers being all or nothing, completely mad devices. Of course, if you want to ride like that then you can. I'm quite taken with this era of strokers, have just bought a 750 Kawasaki triple. This makes the Yamaha feel a bit tame, though I haven't become used to the bigger bike's handling yet - it's dead easy to throw it off the road! Think I'll be holding on to the Yamaha twin for a while longer.

Dave Haines