THEY APPEARED IN MY MIRRORS, coming up fast on the outside. It was inevitable really; the Power Valve is like a red rag to a bull with these people. The 2.8 fuel-injected Capri pulled alongside at the next red light, the designer-labelled South-London fly-boy gunned the engine and the peroxide Barbie doll beside him simpered and smirked through the window. Right pal, you're dead meat, I thought as I blipped the throttle and spread a blue haze of two-stroke fumes over the proceedings.

The lights went to amber, the Yamaha's engine screamed to 6000 revs as I failed to keep the front wheel on the ground, while a long way behind me the Capri was spinning its wheels and going nowhere in a hurry. Two miles later an RSI600 Escort pulled up alongside me and gunned bis engine. Will they never learn?

Since the RD350LC first appeared in this country it has been adopted wholesale as the ultimate street racing machine by the brain-out brigade. You only have to go to The Hill, Chelsea Bridge or Box Hill to see the kind of Absolute Lads who are buying Elsies. The combination of silly performance and a sensible price tag has proved irresistible to the impoverished masses of this beleaguered isle.

Well, now all you YPVS boys will have to get busy with your riffler files because the newest Power Valve is in town, and a real ring-dinger it is too. The '86 model is the same as last year's, except more so. Aside from a few cosmetic bodywork changes, the 347cc engine has benefitted from modifications to cylinder porting and combustion chamber shape.

1 The inlet port timing and shape has been altered, 3 and a secondary port has been added to link the § inlet and scavenge ports, resulting in smoother 5 inlet pulses. The combustion chamber is now

2 wedge-shaped to give a better combustion process than the old-style dome-shaped chamber, and bean can silencers have been added.

Despite the pitiful whining you may have read elsewhere about the LC not making any more power than last year's offering, take no notice. The 1985 Power Valve made 47hp at the back wheel on Motodd's dyno last year; the '86 version managed a staggering 56. lhp at 9000rpm. Hmmmm, something a bit fishy about this — Yamaha claim a significant power increase, but 20 per cent is a little hard to swallow. Undoubtedly the engine mods, the new power-jet carbs and the exhausts should boost output, but being nasty suspicious types we suspected that this particular bike may have been tweaked in Mitsui's workshops. So off we went to Dabbs' two-stroke tuning specialists, Hyperdrive Research, to see what naughtiness had been perpetrated on the Power Valve's internals.

And there it was... conclusive proof that Mitsui had done absolutely nothing to it. What we had here was an exceptionally good example of the breed, capable not only of walking all over last year's LC but showing a clean pair of stingers to NS400s and giving GPZ600s a hard time. A quick look at the comparative dyno chart at the end of this test will show you exactly how much more power this particular beast makes over its predecessor. Impressive, innit?

Although the new Power Valve doesn't feel that much quicker, a quick dice through South London with an '85 350N had me pulling away from him noticeably all the way through the rev range, particularly when the power kicks in at 7500rpm. In fact the 350 really suffers from a schizophrenic nature. Below six grand it'll burble around in a very sedate fashion, behaving for all the world like a CB350S, but above that it becomes a mad-eyed screamer up to 9000 revs. It's actually pretty daft having a 10,000rpm redline because after nine grand the ignition timing is so retarded you feel like you've ridden into a brick wall, the power drops off that sharply. Keep the engine revving between 6500 and 9000 and you'll be rewarded with adrenal overload, cardiac arrest and more speeding tickets than you could shake a rotary burr at. A plea of insanity or diminished responsibility won't cut any ice with The Beak either, so you'd be well advised to keep an eye on the rather blurred view in your mirrors.

The problem with this enormous increase in power is that it now shows up the shortcomings in the frame and suspension departments. What makes Honda's NS400 such a little beaut is useable performance allied to a brilliant frame/suspension package. The Yam's frame and front end have never been all that clever, and now it will start to tie itself in knots if you push it too hard. Okay, so 95 per cent of the time it will handle properly, but push it that extra five per cent and you'll find that determined NS rider will be past while you back off and wait for everything to settle down. Logically, the next step for the Power Valve is a Deltabox frame like the TZR250, but going that route would almost certainly price the Power Valve out of its market and it would end up as just another over-priced race replica. Maybe a modified frame and some beefier forks would do it.

To all intents and purposes the forks and rear shock are the same as last year, the only difference being that Yamaha have done away with the remote pulley adjustment system for the rear shock. Apparently this is because the rubber belt was prone to snapping; now adjustment is via a C-spanner round the black collar at the top of the unit. I found that for my 12'/2-stone the best set-up was number four preload at the back and llpsi in the front forks. Cost cutting rears its ugly head again here because there is no linked system at the front, and it's pretty difficult to get exact pressures in both fork legs.

Cosmetically, the new Power Valve is an improvement over previous offerings. New tank, seat, sidepanels and tail unit mean that the seat height has been lowered by an amazing ... 1cm. Yamaha say this means the rider sits 'in' the machine for improved air penetration and reduced frontal area. It's a well known fact that most people are taller in the morning than later on in the day, so to get the most out of the improved aerodynamics I suggest you only use your Yamaha after lunch. Having scoffed at these somewhat ludicrous aerodynamic efficiency claims I have to admit that the new LC was slightly more frugal than last year, returning nearer 40 miles to the gallon rather than low to mid 30s. All well and good, until you realise that the tank actually holds two litres less than previously, so you're still not going to get more than 140 miles on a full tank. In reality you can expect to have to stop for petrol once the trip registers three figures.

As with the previous model, the LC's dual opposed piston front brakes are superb and monster stoppies become almost irresistible. The back disc still lacks feel and locks up too easily, but with such good feel and response at the front you'll rarely need the rear brake. When I tested the Power Valves last year they came equipped with Michelin A48/M48s and Pirelli MT58/59s rather than the OE Yokohama 202s fitted on this particular machine. 1 really rated the Pirellis, liked the Michelins, and now I dislike the Yokohamas. They grip just fine in both wet and dry, but are very sensitive to white lines and road irregularities and feel very twitchy.

Top speed on the LC is marginally up on before and the best mean top speed managed was 116mph, which relates to 125mph on the clock. Not staggering in itself, but the way it gets up there has your eyes stuck to the inside of your visor, your bum sliding back along the seat and a lunatic grin spread across your face. The only thing that's going to wipe that smile off your face, apart from an appearance by the boys in blue, is maintaining a steady 70mph in top gear at 5000rpm. The only serious vibes occur at these revs, so to alleviate tingling extremities you really have no choice but to cruise at 85mph. Which is not a problem as you can keep up speeds well in excess of a ton without too much discomfort.

The switchgear, clocks and cycle parts, with the exception of new wheels, are identical to the previous Power Valve -excellent. The new wheels are lighter than before and are also a delicate shade of vermilion: understated elegance isn't the description that springs to mind immediately, but they are in keeping with the Yam's flashier new paint scheme. In fact the overall look of the Power Valve is flashier and more like that of the 500LC. The fairing remains unchanged, but the sidepanels have pseudo exhaust bulges which don't look like fooling anyone. The only slight problem with the new sidepanels is that you have to remove-the pillion grab rail to take them off, but it also means that you won't get people thieving them every time you leave the bike for more than 30 seconds. Mind you, there's still no guarantee that the whole thing won't have gone walkies while you're not looking. The Power Valve is still one of the most likely machines not to be where you last left it, and I reckon each bike should be supplied with a very hefty lock.

In fun and performance-for-your money terms it's very hard to beat Yamaha's 350YPVS. It's fast, it's furious, it's cheap to buy, run and insure. On the British market there's nothing to compare it with: at S2259 it's £840 cheaper than an NS400 and sensibly steers clear of the race-replica tag that has hamstrung sales of that particular beast. Now that the Elsie has more power and sharper looks (and is only £120 more than the '85 model) it'll continue to reign supreme in the budget street racer class until one of the other manufacturers muscle in with a cut-price screamer of their own

Source Motorcycle International 1986