I've lots of experience making old engines run. My immediate suspicions centred on the ignition system. The spark at the plugs was yellow rather than blue. New plugs, same trip. Cleaned and set the points to no avail. New condenser. Nothing’s ever that easy but receiving about 10000 volts via the HT lead put me on the right track. Car coils with new HT leads and caps resulted in a bright blue spark. But still the engine only stuttered rather than started. The next logical place to look was the carburation, although I could smell petrol getting through. The rubber manifolds were intact, as were the diaphragms. Some jerk had screwed the pilot jets right in.
After a bit of trail and error I got the engine sounding positively enthusiastic but not quite firing. The final piece of the puzzle was an OE air filter clogged up with 32000 miles worth of grime. A few strategically placed holes revived the flow characteristics and the motor finally fired up. Nothing’s quite that easy, is it?
The top end rattled and the gearchange was way past its prime. The top end was down to a dead tensioner and camchain, the gearbox had worn out selectors. Whilst I waited for the bits to come from Japan, I set to the chassis with a vengeance. Rust had almost ruined the guards and seat base but GRP and paint revived them. The frame was rubbed down and touched up where necessary. The forks and shocks were handed over to a mate who had a small engineering workshop in his cellar and was able to renovate them for fifty quid. The wheels were painted silver, the chrome long since lost to the mists of time. An expensive round of consumables completed the renovation effort.
What I had was a plain and simple vertical twin of 325cc, about 35 horses and 360lbs. Utterly conventional in almost every aspect, the CB350 was one of the best selling motorcycles ever in the USA, although licensing laws made the 250 version much more popular in the UK. Its looks are somewhere between bland and classic but grow on you with time. My bike was a dark green that still shone up nicely after a bit of T-Cutting.
Once the engine had been reassembled, a relatively painless process, I was all set for some serious riding. Already, there were fitted rear-sets that matched the flat bars much better than the forward mounted pegs that came stock. The seat left me feeling perched atop the machine, but other than that the riding was really easy. A moped graduate would have no problems if he were allowed aboard such a machine, making rather a mockery of the 125 laws.
To be sure, I was initially aware of a top heavy feel that tried to tilt the machine into slow bends but my body soon compensated and I was kicking the bike around like the proverbial juvenile delinquent. Braking, with a TLS front and SLS rear drum, was close to brilliant loads of power and plenty of feel.
The refurbished suspension was rather stiff for modern, ruined roads but stopped any wandering or wallowing. Performance was up to 250 Superdream levels but lacked any kind of viciousness or wickedness; I could just crack the ton in neutral conditions, maybe 105mph flat out down a steep hill. Even when thrashed into the red at unlikely revs, there wasn’t very much vibration. Surprising on a bike of this age and mileage; a testament to the basic correctness of the design and an indictment of nasty things like Superdream balancers that Honda later inflicted upon the world.
This style of older Japanese bikes have taken over from ancient British twins as righteous sickles. Don’t laugh, they have the same kind of performance, are still cheap to buy and run along without too much expense or effort. All attributes that Bonnies and Commandos used to have but they've priced themselves out of the market, these days. If you don’t believe me just look around at the number of cheap chops that’ve been built around old Jap twins. A sure sign of the times.
I felt pretty secure with the Honda's engine but slightly worried by the stories of the chassis cracking up. I'd noticed with alarm the appearance of great gobs of rust at the upper shock studs. My friendly local mechanic tested them with his largest hammer, got the right hand one to fly off. He said not to worry (something about the alarm in my face), the welding torch would solve all. And it did, praise be to primitive technology.
Next on the list of possible disasters was ageing alloy in the drum casings. It’s not unknown for old hubs to crack up after 20 years of service. A weekly jet wash and inspection kept some kind of peace of mind. However, after about 6000 miles the rear drum started to crack up. Alloy welding didn't inspire much confidence in such an important component. A used back wheel was found in the small ads of one of the other magazines.
There was no guarantee that this wasn’t about to disintegrate but in the greater scheme of things it was a risk I was willing to take. bin Eventually, some 14000 miles further down the line I ended up with a pair of Bonnie wheels (with concentric hubs), forks and shocks, making the similarities between the breeds all the more noticeable. A couple of Brit bike fanatics made nasty noises about my misuse of Triumph components but in general the little Honda was received well wherever I went.
The stiff Triumph suspension and powerful brakes allowed me to ride the Honda right at the limits of engine performance. With 52000 miles on the clock such levels of abuse couldn't last for long. Sure enough the pipes began smoking and top speed decreased to a mind nurturing 80mph. The top end was OK but the bores and pistons looked like they’d been around the clock a few times. Replacements were already to hand, in the form of CB250K3 barrels bored to take high compression pistons, a popular move back in the seventies when the porkers were unable to tell that the motor was bored to 325cc. Still useful, today, as it brings down the cost of road tax and insurance (damn, I should've bought the 250).
Out of sheer respect for the motor I bunged in new top end gaskets and added a shiny new set of exhausts. The engine, given a gentle bit of running in, managed to push the Honda to all of 110mph. Some replica jockeys were quite surprised at the way the bike would cruise along at 95mph (in excellent comfort, I might add) and, also, at the angles of lean it'd take (the stands had their prongs ground down and the Triumph suspension made the bike ride an inch or so higher). Acceleration was, it has to be admitted, rather stately by modern standards, a lot of effort needed to see off derestricted TZR125s, and the like.
Much to everyone’s annoyance (I mean there’s nothing like getting up the nose of people who spend thousands on new bikes, is there?) the CB ran with an almost miraculous lack of faults to 82000 miles when the camshaft bearings, rockers and valves were all dead meat. The thing with these kind of bikes, rather like MZ250s, is that along the way you tend to collect all kinds of rats and out of this accumulation of junk, er, valuable future classics, I had the necessary bits to fix it.
However, the purchase of a bargain priced FZR600 with ruined plastic meant I had my hands full. This was my first replica and the performance turned out to be so stunning that I left the Honda to rot. There’s no excuse for this kind of neglect, other than rampant self-indulgence. If any UMG readers want to buy a CB350 plus several rat CB250/350s then drop me a line via the UMG. About £250 seems right! CB350’s are neat motorcycles with a future.
John Trent