I have owned my Honda CB350K4 since 1976. I did not buy it brand new, it was already two years old with 12500 miles on the clock. It had been standing in the local dealers for three months looking for a new owner. It was absolutely standard even down to awful OE Jap tyres that were swapped for a set of Avons as part of the deal.
Thus equipped my first run on the bike was not very frightening nor very exciting. The twin cylinder, OHC engine didn't have much of a sharp power output, what power there was just flowed gradually with a bit of a surge at 6500rpm, from which revs (at least until 9500rpm) the motor smoothed out nicely. It would buzz along at an indicated 80 or 85mph without any apparent problems or the need to rush up and down the five speed gearbox like a lunatic. But getting a ton on the clock was very hard work indeed.
The handling was not particularly precise, the soggy back end letting it weave a little, but it was by no means dangerously decadent like a H1 or even some old British stuff. With 87000 miles on the clock, I have had Girling, Koni and currently Hagon (an update on the old Girlings) shocks on the back, all of which eradicated most of the wobbles. I once tried a set of Michelins which made the handling well dangerous, so it was back to Roadrunners before they wore out.
The front forks were adequate for the first 20,000 miles and then were junked for some Marzocchis (off what I don't know, they were laying around in the local breakers) along with a set of alloy yokes and gaiters. The stock bottom yoke is a very flimsy item and ought to be checked for cracks or distortion as it can't hold the front wheel up if the clamp screws are taken off! The Marzocchis were stiff for the first 10,000 miles but are now well bedded in.
The same could be said for the engine. Perhaps the fact that it only knocks out a mild 32 horses from its 325cc capacity helps to explain why it's such a long lasting unit. The massive four bearing crank (with pistons moving up and down alternatively) is still there, as is the gear primary drive, clutch and gearbox. The top end has not been quite so lucky. Burnt out exhaust valves at 35000 miles were not exactly amusing, but a £25 used cylinder head fixed that. It's only had one rebore at 65000 miles and the resultant new set of pistons. The camchain was replaced at the same time, although the tensioner (a non auto job that needs a fiddle every 5000 miles) is still working okay!
One tedious problem, common to many old Jap engines, is a leaking pushrod seal. The seal leaks because it is next to the final drive sprocket and gets doused in lots of crud. It can be pulled out by inserting a screwdriver in it at an angle and a new one bunged in without taking any more than the engine sprocket cover off, but has to be done every 5000 miles. It's worth checking this area for oil leaks anyway, as a broken chain may have holed the crankcases.
Another problem, rotting rubber carb manifolds, especially if the airfilter box has been removed (a waste of time, it doesn't go any faster) that cause erratic running and poor starting once they start to leak. Similarly, diaphragms on the CV carbs can rot. Silencer rusting is endemic to the breed as well, although just about anything with a passing resemblance to a silencer can be bunged on without upsetting the carbs. I bought two new sets whilst they were going cheap, so have a spare if the bike ever gets classic status.
Engine maintenance has not been a great chore. Change the oil every 1000 miles, at every second change do the points, valves, carbs and bung in a new set of plugs. I do the latter because it's the only way to maintain first kick starting, the electric foot having long gone to that great scrap heap in the sky. Which brings me neatly to the battery. They seem to last only 7500 miles, although the fact that the bike is still on the original wiring, regulator and rectifier may help explain that.Consumables are reasonable.
The (still excellent) TLS front drum shoes need replacement every 17500 miles, the back every 25000 miles - I snapped up the whole supply dead cheap from one dealer who was clearing out old stock, so I'm set for the next 100,000 miles. Chains went for a modest 12000 miles on new sprockets which needed changing on every second chain (or chain life was about 5000 miles) until I adapted a CD175 full chain enclosure which nearly doubled chain life. Roadrunners last 12000 front and 10,000 rear, reasonable in that they still grip well when worn down to the limit.
Handling is better than new with modified suspension as the frame is quite hefty mild steel that maintains its resilience well with age. The same can't be said for the paint - I had to have it stoved enamelled at 32500 miles, taking the opportunity to replace the dodgy swinging arm bearings. The tank and sidepanels, though, are still on the original paint and respond well to the once monthly shine up. Same can't be said for the chrome guards. The front rusted through at 30,000 and the rear at 42000 miles, both replaced with new ‘uns that were undersealed and then coated on the external surfaces with a clear varnish. They still look okay. The wheel rims were well rusty at 35000 miles, replaced with stainless spokes and alloy rims that still polish up well (but talk about tedious).
The engine sidecovers are bead blasted every 15000 miles (as were the barrels and head when the rebore was done), so it's just a matter of some Solvol and elbow grease to get the engine looking nice. Not bad for a 17 year old bike. All the silly crosshead screws have long been replaced with allen bolts although some of these have some ragged edges to their seats so that allen keys start slipping.
There are four threads in the alloy casing that have been repaired with Araldite......the engine doesn't leak any oil save a slight weep from the cylinder head gasket (that was there from purchase and didn't go away even with new gaskets) and uses about a pint between oil changes.
The engine still seems to push out the same kind of power as when I bought it, at least up to 85mph; after that it's such a tedious business to get up any more speed that I've all but given up. It involves revving the bike dangerously close to the redline in the lower gears and the poor old motor starts vibrating badly when I do that - no way to treat an old friend.
I am now 48 and the Honda has been used for everything. It has occasionally been slung to the back of the garage when funds have allowed the purchase of a newer, faster multi but when my income takes a dive I always seem to sell the new bike and go back to the sensible old Honda. It doesn't seem to resent this treatment. Indeed it has never once let me down on the road, enough in itself to mark the bike as a good ‘un.
Its age has not deterred me from taking it on llong rides. I recently did 3500 miles in two weeks running around Europe without a hitch. I even saw quite a few CB350s on the Continent in as good, if not better, nick than my own, although they are rare in the UK. Having tailored the bike to suit my own tastes - flat bars, rearsets, stock seat but with denser foam on a homemade GRP base after the steel effort rusted through - I am quite happy to breeze along between 70 to 80mph for several hundred miles in a day.
Mileage on that tour was around 60mpg, a figure that shocked my GS500E mounted companion (he was getting 45mpg at the same speed). I must admit that he could have ridden off into the distance on his bike, but my brief ride on it left me curiously unimpressed - yes, it accelerated well and would do the ton no problem, but it handled very weirdly (a twitchy little bugger) and seemed to lack character. On the Honda I always felt like I achieved something after notching up a couple of hundred miles and felt part of the vehicular experience.
I've never got the CB350 below 55mpg and have done as much as 75mpg when I've been desperate to save money. The bike can be slammed through town traffic with a great deal of ease; narrow, light with predictable and adequate power, I've often surprised many superbike owners with some skilful riding - it really gets up their nose and they often try to wheelie their lumbering beasts through too small traffic gaps.
Things that could be improved - the notchy gearbox that needs very careful changes when going up the box to avoid false neutrals, conversely, less clutch drag at traffic lights that would allow me to find the proper neutral; throttle cables that wear out every 10,000 miles despite copious greasing from new (they are a pain to replace); rust prone cycle parts and exhausts that should be stainless steel (that would cost more than the bike was worth); and, perhaps, a bit more power.
For the kind of money I could get if I sold the CB350 there is nothing that I could buy that could replace its versatility or dependability. It seems to me to have all the virtues of Brit twins with none of their reliability problems, and just to rub in it, is far more practical that modern Jap stuff.
Ian James
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There are old Hondas that survive against all the odds. This one cost me all of fifty notes. The way I got it home was by pushing for four miles. Ouch! The chassis was a bit rusted but intact. Nothing new consumables and a bit of painting wouldn't sort. The engine was an entirely different matter. There were two in fact. A CB350 twin in bits dumped in the top box and a cardboard box strapped on to the seat. The engine in the frame was, wait for it (grab the sick bucket), a CB250G5 unit.
There was no hope that either motor would ever run again. As well as sharing knackered cylinder heads, which was expected, the crankshafts were also shot. What was needed was a crashed bike with a newly rebuilt engine. What I ended up with was a fanatic's load of CB350 parts. His main bikes had gone up in smoke in a fire. I was assured there were enough bits to make three engines. The transit load cost £200.
There was a complete bottom end that where it wasn't filled with oil was greased. It seemed pretty obvious that no-one would go to that trouble unless it was a good ‘un. There were about ten sets of pistons and barrels but only two decent heads. The only thing I had to buy was a new camchain. The rebuild was very straightforward with the aid of the manual, helped along by having a choice of new gasket sets to hand.
The electrics fitted in the chassis bore little relationship to what was in the workshop manual. Anyway, I put the motor in and wired up the ignition to a new battery. One new set of spark plugs and about fifty kicks later the engine growled into life. The OHC unit has a distinct off-beat note that by modern standards is rather loud.
The Honda has a sensible riding position, but I felt a bit perched above the compact machine and in my initial excursions the handling seemed a trifle loose. It already had Girlings out back and the front forks were reassuringly firm. The swinging arm bushes were shot and there were none in my cache of spares. The local Honda dealer only just restrained himself from telling me to piss off but after fifteen minutes of muttering under his breath he came up with the part number. Come back in six weeks, he said! Aaagh!
I approached the local back street merchant who said no problem, come back tomorrow. He had a big box full of various bushes and felt sure that one set would fix. I left him to it, was pleasantly surprised to find that he'd done the job (£20). I'd already put on a new set of Michelins (they were cheap), so there seemed nothing for it but a bit of speed testing on the local bypass.
That was how I came to get a ticket for 97.5mph and a lecture on riding twenty year old motorcycles in a sensible manner. The Honda had weaved once past 75mph, which I think was just down to an inadequate frame as nothing I tried subsequently improved matters. The frame was originally designed for the late sixties Honda CB250K1, at a time when the Japanese were just making poor copies of British frames without a true understanding of the interaction of weight distribution and geometry.
The Honda was by no means the worst handling bike of the era, most of its nastiness tamed by upgraded suspension and a firm hand on the bars. Weighing 360lbs, maybe 400lbs with a full load of fuel and oil, made for reasonable stability over bumps and in crosswinds without needing to take up weight training to throw the little twin through traffic.
There were some problems in town. This era of Hondas are famous for their dragging clutch and awkward gearbox. It took a while to perfect the art of coming to a stop in neutral. If I came to a halt in gear with the clutch pulled in, the box would lock solidly, refusing to entertain the idea of going into neutral. As soon as I moved off it would free up, but waiting at the junction the bike would creep forward as the clutch dragged. Hitting the front brake stalled the engine. The box would then go into neutral straight away and come to life on the kickstart first time. There was an electric start but it just rumbled away to itself rather than turning the engine over.
The other problem in town was down to the suspension. It was fine with a bit of speed up, but at commuting velocities it barely moved, the bike being shook over pot-holes and minor bumps going straight through to my spine. It was more like riding a bicycle than a motorcycle, the way it twitched from bump to bump.
On the upside, it was commendably narrow, easy running below 6500rpm and able, when the going got tough, to burn rubber with the best of them, the revs shooting all the way up to 10,000rpm in second and third gear. It wasn't a good idea to try that trick in first as the change up to second usually ended up in neutral. The motor made such a row that it became incredibly embarrassing. I usually tried to take off in second, something the engine could manage without an excess of clutch slip except when faced with near vertical hills. Honda claimed 36hp from the short stroke 325cc twin but it never came viciously on cam, giving an impression of mildness.
Top speed was 105mph on the clock but it wasn't a very pleasant experience. A combination of weaves and vibration meant I didn't hold it for more than a few moments. 75 to 80mph cruising it could handle all day long, with just the gentlest of thrumming from the engine and the mildest of weaves that not even quite vicious bumps would turn nasty. The chassis was neutral in bends, neither running wide when accelerating nor trying to leap off the road when the throttle was backed off.
Braking in bends was okay, the TLS front and SLS rear drum had excellent feel with none of the dangerous grabbiness of discs of this era. The front drum was powerful enough to twist the forks from high speed stops but just one heavy workout would have it overheating, fading away to almost nothing.
This was a limiting factor when trying to ride fast down the back roads. The first time it happened I was hoping to lose 20mph before swinging over for a sharp left-hander. Instead I ended up riding straight off the road when the brake failed to work. Luckily, there was a gravel strewn track, so we skidded along that for a hundred yards before hitting the grass and toppling over.
There was no apparent damage, except to my ego, so I rode home cautiously, wondering if the shaking front end was due to my nerves or some hidden damage. When I'd recovered they were still there, the steering head felt loose. Rather than tighten this up I decided to take the forks off as I wanted to test them for straightness. Never undo the lower clamp bolts with the front forks and wheel still attached to the bike. I was gobsmacked as I knocked the second bolt out, the front wheel sliding forward as the lower clamps were massively deformed - they have no strength unless the bolts are fitted!
They were unusable but I found some replacements in the stash of spares. The steering head bearings were either cracked or pitted, not an ounce of grease in evidence. New bearings removed the head shaking but did nothing for the high speed weave.
The engine had been running reliably for about 6000 miles when it started misfiring. It felt like partial fuel starvation so I looked at the carbs. One of the rubber diaphragms had a small crack; predictably the spares were in an even worse state. Superglue to the rescue. I felt sure I'd solved the problem but it wouldn't run on that cylinder. After much head scratching I found that the rubber manifold was cracked, I must've traumatised it when I'd pulled the carb off. Fortunately, there was a spare on one of the other cylinder heads.
That fixed the poor running until 2000 miles later huge quantities of oil started coming out of the clutch pushrod seal. This is a chronic problem on old Hondas because it's right next to the drive chain sprocket and gets covered in crud. The seal can be brought from bearing factors and was easy enough to pull out. I always used a bit of Superglue on the seal to make sure it doesn't fall out. Later Honda twins relocated the clutch mechanism to above the clutch on the other side of the engine - now you know why!
The engine was a bit of a pain on maintenance, needing a 750 mile oil change, carb tune, valve check, points setting, chain soaking and casing polish (they had been bead blasted in the past). If it didn't get that fuel would go down to 40mpg (from 55mpg), the gearbox would become intractable and the vibes vicious. As I'd got it so cheaply I shouldn't have complained but it became too much hassle every time I took the bike on a long weekend's tour, although the Honda was comfortable for 300 miles in a day and the consumables, except for the chain which always needed an adjustment, didn't seem to wear.
When someone came up to me with an offer of £750, I, kind chap that I am, said he could have it for a grand with the garage load of parts thrown in. And he did!
James Kilburn
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I could smell a bargain a mile away. The advert in the shop window told of a 1973 Honda CB350 twin, a non-runner for 25 notes. No phone number so I had to make the trek on spec. The bike was whole, a bit rusty in places and the motor still turned over. Better still, the owner's old man would deliver it to my house free of charge within the hour. The deal was struck and the adventure begun.
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 condensor. Nothing's ever that easy but receiving about 10,000 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 trial and error I got the engine sounding positively enthusiastic but not quite firing. The final piece of the puzzle was an OE airfilter 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.
These 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.
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 okay 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 TZR125's, 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 MZ 250s, 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 CB250/350's then drop me a line via the UMG. About £250 seems right! CB350's are neat motorcycles with a future.
John Trent