The Honda CB250 was no ball of fire, but mine got close

“Oi mate, yer bike’s on fire!”

The shout from the taxi driver who’d pulled up alongside me at traffic lights in west London made me look down at the ageing CB250 whose throttle I was desperately revving in an attempt to prevent the engine from conking out.

The cabbie was right. Thick smoke was belching out behind me from a twin-cylinder motor that had been running increasingly badly, and now looked and sounded as though it was about to explode.

With a heavy heart I waited for the lights to change, then eased the gold-coloured Honda off the road and let its motor die, wondering how I had been foolish enough to get involved with such an unreliable heap in the first place. And more urgently, how the hell I was going to get home.

At this point I should add that the above scenario happened to my own shabby CB250, more than 40 years ago, not to the clean and well-behaved machine pictured (which was borrowed from Japanese classic specialists Oxford Classic Honda). That smoky incident, the result of poor maintenance, was unrepresentative of the CB250, which was one of the models that helped Honda establish its reputation for reliability and high-quality engineering in the early Seventies.

Although the CB250 parallel twin couldn’t match the performance or glamour of Honda’s fours – or of its 250cc two-stroke rivals from Suzuki and Yamaha – it was one of the firm’s most popular and long-lasting models. The CB, after all, was a direct descendent of the sporty 250cc CB72 of the early Sixties, which had first shown that Honda could build exciting bikes rather than just small-capacity commuter machines.

The CB250 had been introduced in 1968, as the sports model of a trio of twins, the others being the CD250 tourer and CL250 street scrambler. The new 249cc engine had oversquare dimensions of 56 x 50.6mm and was similar in many respects to earlier Honda units, including in its use of a single overhead camshaft with drive by a central chain, and a 180-degree crankshaft.

One key difference from Honda’s previous twins was that the new engine’s cylinders were set almost vertically, instead of angled forward as before. As the sporty model, the CB followed Honda tradition by having twin carburettors, which helped it produce a maximum of 30bhp at 10,500rpm, a few horses up on the 27bhp of its single-carb siblings. Both CB and CL had five-speed gearboxes; the CD made do with four.

The twin-cradle frame, which had a pressed steel spine under the tank, was similar on all three models. Even the suspension and wheels differed little, although the CL had gaiters for its forks. The CB was treated to a twin-leading-shoe front drum brake, instead of single-leading-shoe like the others, and also featured a rev-counter alongside its speedo.

Honda made few changes to the CB250 over the next few years, though the original 250K model’s petrol tank rubber knee-pads were dropped for the following year’s K1 model which, like the following K2, had a slightly more angular tank than the 1971-model K3. The most popular version in Britain was this model, the K4, which arrived in late 1971 and was sold in larger numbers during the following year, which was when this particular gold-coloured bike was first registered.

All those years ago I can remember being pretty impressed with my CB250’s speed, when it was running well. That was hardly surprising, as the bike I’d been riding before buying it was an SL125, with half the number of cylinders and horsepower.

“My” CB250 had previously given me a hugely entertaining moment when still owned by my mate Chris, whose dad had come out of the house for a look, and announced that he’d ridden motorbikes in his youth. The old boy proceeded to get on the Honda, rev it up and drop the clutch – at which point he shot across his garden, totally out of control, ending up under a hedge alongside the bike…

That old Honda never generated quite such excitement again, and nor did this one on my more recent ride, but the 30-horse twin was capable of a fair turn of speed. Its forebear the CB72 had been rumoured to be capable of 90mph on a good day, despite a claimed output of just 24bhp. Something didn’t quite add up, though, because American magazine Cycle World had managed exactly that top speed from the CB350, which at 36bhp was 6bhp more powerful than the lookalike CB250.

The CB250’s true top speed was probably about 85mph, although given my experiences with my own bike, I didn’t hold this one flat-out for long enough to check. Instead I spent much of the time cruising along at a gentle 55mph and about 6500rpm, at which speed the Honda felt very smooth, and still had some not-too-dramatic acceleration in hand.

Keeping the revs down meant missing out on acceleration, because the smaller motor liked to be revved. Or, as Bike magazine’s tester put it in 1972, “If you enjoy mixing it with the bigger boys, then you’ve got to grab that suicide handle and keep it cooking.” There wasn’t much power below 5000rpm, and to get the best out of the Honda you had to keep the tacho needle between 7000rpm and the red-line at 9200rpm.

I hadn’t expected too much of the handling, given the Honda’s age and relatively crude chassis design, but in fact it cornered respectably well and was stable at speed. I’d been wary of the old and cracked Avon tyres, but thankfully they still held the road respectably well. I enjoyed flicking through bends on a bike that weighed just 156kg, and felt fairly light and agile.

Suspension at both ends was slightly soft and vague, but pretty good considering its age and the fact that the CB250 had always been rated as highly for its comfort as for its handling. I was also pleasantly surprised by the brakes, especially the twin-leading-shoe front drum, which gave reasonably powerful stopping.

Despite that, Honda soon updated the CB with a disc front brake and six-speed gearbox. For 1977 it was revamped with slimmer styling and a two-into-one exhaust to create the CJ250T. That in turn was replaced a year later by the CB250T Dream, featuring a bulbous tank and new three-valves-per-cylinder engine.

The original, familiar CB250 was gone, but it would not be forgotten. Especially by any former owners who had suffered the shock of glancing down at the traffic lights to see their example of Honda’s fine engineering belching smoke and about to expire.

1972 Honda CB250K4

You’ll love: Its all-round performance and reliability… usually
You’ll curse: Any mechanical bodges by a previous owner
Buy it because: It’s fun to ride, has Seventies style and is great value
Condition and price range: Project: £2500 Nice ride: £3500 Showing off: £4500
Engine: Aircooled sohc parallel twin
Capacity: 249cc
Maximum power: 30bhp @ 10,500rpm
Weight: 156kg with fluids
Top speed: 85mph

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