Soichiro’s favourite Honda – the CB350 Four
The four cylinder Honda 350 cc models were manufactured between 1972 and 1974. The first model was the CB350F and came in three colours – (the most popular) Flake Matador Red, Candy Bacchus Green and the not so popular Custom Silver Metallic. All three colours featured White and Orange stripes. For 1974 the CB350F1 model was offered with no changes apart from new paintwork named Glory Blue Black Metallic and with gold stripes. My limited research tells me that the Glory Blue Black Metallic colour was sold mostly for the North American market. The CB350F models all featured conventional Honda technologies and styling for the early 1970’s era. The frame, suspension, wheels, lights, instruments and brakes were all conventional Honda components but the tiny four cylinder air-cooled engine was the jewel in the CB350F’s crown – a very smooth unit. To quote the popular description of the time “it runs like a Swiss watch”, and this was the real attraction of the CB350F and this charm endures to this day. The 347 cc engine features a single overhead camshaft operating two valves per cylinder; a conventional wet plate clutch and a five-speed transmission. The crankshaft was supported by shell bearings – a departure from the previous CB350 twin models which used ball and roller bearings. The external finish of the aluminium engine castings took the CB350F to a new height of finish when compared to the previous model. The Japanese had already been experts at die casting techniques for many years and this experience was on display. The weight of the CB350F was its Achilles heel – a whopping 19kg more than the CB350 twin. That’s a lot of extra weight for a 350 cc motorcycle to bear. The engine output was 2 hp less that the twin, and this all added up to making the four slower in acceleration and in top speed. The standing quarter mile time was 15.61 seconds with elapsed speed of 131.9 km/h, against the twin’s 15.3, although these figures varied greatly according to which magazine did the test. This lack of performance is most probably why the CB350F was not ever imported to the United Kingdom market. The surface area of all the multiple engine components and the resulting friction was the culprit. This engine was a compromise of performance against life. But the easy to ride nature plus the sedate and smooth power delivery of the CB350F were very good reasons why it was Mr Soichiro Honda’s favourite Honda model. The four separate exhaust header pipes and mufflers with bright chromium plating were unique to the CB350F. They were tucked alongside the engine cleanly, but for the real racers of the time – a four-into-one was the only option to raise the ground clearance and to produce that beautiful sound. The shape of the mufflers is actually reminiscent of the megaphones utilized on the exotic multi cylinder Honda racers of the early to mid 1960s. Should you get the chance, stand behind a CB350F when it is at idle (or any CB500 or CB750 four of the early 1970s), and listen to the sound when it accelerates away from you. They sounded like nothing else. During the 1970s, owning any Honda four and being a member of the Honda Four Club meant that you were in exclusive company. The CB350F featured minor changes between the markets where they were sold. The main markets were Japan, North America, Germany, France, with other markets supplied with “European Direct” and “General Export” models, Australia receiving the General Export model. The changes were all cosmetic and limited to the speedometer (either MPH or Km/H), tail light (three different types), indicator lamps (two different types), chain cover (black or chrome), and the rear vision mirrors.
“Should you get the chance, stand behind a CB350F when it is at idle (or any CB500 or CB750 four of the early 1970s), and listen to the sound when it accelerates away from you. They sounded like nothing else.”
Living in the ‘70s
My mates and I evolved through the Honda models as schoolboys, starting with the single cylinder trail range, graduating to the CB350 and CB360 twins with the one lone CB350F in the crew. Unfortunately our mate rode his CB350F slowly like an old man (sorry) which created a lasting and poor impression to most of us. We affectionately nicknamed the CB350F “the slug”. As budding road racers on our Honda twins, we added two-into-one exhausts and raised foot pegs to improve ground clearance – we could improve the breed …. but these smaller midrange Hondas were only one step up the capacity ladder to the multi cylinder engines we dreamed of – CB400F, CB500 and CB750s followed, before we purchased those open class DOHC offerings manufactured in Kobe. In 1975 the sedate CB350F evolved into the exciting CB400F – complete with that stylish and exotic exhaust system featuring the four-into-one header pipes and a single muffler – functional both for aesthetics and for extra ground clearance. Marketed as the “European riding position”, the low handlebars and rear set footrests coupled with the slim seat and large fuel tank all meant business – a Café Racer – and it was made in Japan! The engine’s exterior featured minor changes to go with the increase in capacity to 408 cc (Japan’s market model was 398 cc to meet their registration laws). Lighter weight and more horsepower gave what we saw as a stodgy old four a new life. There is only an extra 61 cc and the four into one exhaust, plus a six-speed gearbox, but I suspect there are other changes to the camshaft and the combustion chambers to substantiate the performance difference over the CB350F. A well ridden CB400F offered only little resistance to the dominant Yamaha RD400 in production racing.
My CB350F
This particular CB350F is a USA model, complete with the high USA specification handlebars, speedometer in MPH, and the large tail lamp. It was imported into Australia during late 2013 with approximately 14,000 miles on the odometer. This Honda was purchased by a private collector based in Sydney, and he displayed it unregistered in his basement along with his other collectable motorcycles. Despite being a low mileage example, the new owner proceeded to spend a large amount of money on refurbishing major components such as the tank and side covers, seat, wheels and the exhaust system. Consequently he came under pressure to reduce his collection, and I was able to purchase the Honda. Unfortunately the new paint on the tank and side covers did not match the original Flake Matador Red on the fork covers, so the entire bodywork was repainted to produce the result we see now. The pin stripes were hand masked, such were the skills of the painter. Also completed were new chrome plating on the shock absorbers, both mudguards, tail lamp housing, rear brake lever and numerous bolts. New zinc plating was completed on most of the bolts and fasteners. Other smaller missing components including a Yuasa battery and genuine handlebar grips were also sourced to make this CB350F complete as it had left the showroom. The genuine Honda CB350F Owner Manual proved quite expensive to source.
Riding the CB350F
After all these years, purchasing a CB350F for my humble collection was an admission – I really do like the tiniest Honda four, and I always loved the styling and that beautiful exhaust system. The handlebar mounted warning light display came straight from the fabulous CB750. My everlasting impression was of a poor performer, but riding the CB350F for the first time in over forty years showed me that I had let my youthful naivety cloud my judgement. The CB350F does actually perform very well; not quite as fast as a CB350 twin, and nowhere near the Yamaha RD350 or Suzuki T350 two strokes which fought out production racing of that era. Take the tachometer above 6,000 rpm and the little Honda really does start to produce some power. It seems as if it really wants to stay there at these higher revolutions and the power delivery is constant right up to the red line.
The CB350F is just too easy to ride, and it rides comfortably and smoothly; perfect for those who have returned to motorcycling after many years and are not so confident with their rusty riding skills. No-one should ever discount taking a CB350F for a long haul trip, such is the comfort for even an older motorcycle (albeit, sedately) approaching fifty years of age; a perfect mount for collectors and enthusiasts who are looking for a totally reliable and comfortable club motorcycle that will get you there and back again, many times. Comfortable two-up riding is a bit of a squeeze. As was the standard practice during the 1970s, change those tyres for a good mid-range performance tyre (Dunlop TT100s look good). And change those “pogo” stick shock absorbers – they look great at a motorcycle display for accuracy and photographs, but are not recommended for any action approaching those hard cornering antics of your youth. The CB350F is quite easy to clean and groom despite the four exhausts – such was the simplicity of the design of the era. It is a pleasure to clean and polish the CB350F, especially with all that bright chrome plating. I never tire admiring those big bike features – a true example of good design and execution.