I was gambling with my life by using a Yam RD350F2 for commuting to work. There was nothing wrong with the stroker twin, other than the heart blasting turn of power come 7000rpm. It was so thrilling that every time I leapt on the bike I wanted to experience it. The nine mile journey thus consisted of insane bursts of acceleration, desperate braking and an excess of narrow squeaks. The traffic density was intense, making the cagers do strange and terrible things.
The RD had quite a lot of torque at lower revs and, at least in stock tune, did not oil its plugs too often when using minimal amounts of throttle. But the call of the powerband was hard to resist and I was becoming very pissed off with the 33mpg economy when caned.
When a one year old Honda CB350S was advertised at a bargain price, I went for a look and decided I had to have it. The owner was so desperate for a quick financial fix, that I knew if I hated the bike I could just sell it on at a large profit. The Honda felt more like a CD175 than a 350 after the RD, but it was very relaxed and easy to ride, with none of the twitchiness of handlebar that afflicted the Yam, admittedly at somewhat higher speeds than the Honda could entertain.
About the only thing that the two engines share is a similar capacity and two cylinders. Even then, the Yam's pistons move up and down alternatively, whilst the Honda's plod up and down together. The latter characteristic is shared with a myriad of old British twins and would result in characteristic vibration had not Honda fitted a chain driven balancer system. This hideous mechanical abortion (just about everyone else uses gears) cause problems on high mileage engines.
The CB350S motor harks back to the Dream and Superdream design, with three valves per cylinder. Developing just 34hp it's very lowly tuned for a modern Japanese engine, which is apparent on the road. There's bags of pulling power from low revs, but it seems to disappear just where the Yamaha is beginning to take off. So mild is its nature that the bike would be ideal for 125 graduates as they are unlikely to get themselves into any tricky situations.
I soon adapted to riding the Honda to work, its sensible nature working its magic on my senile delinquency. The trip to the office took no longer, though, because the CB was that much easier to control and manoeuvre that any speed lost to the flat out bursts on the RD were easily made up by the bike's ability to slip through incredibly small gaps. As the months went by the traffic became ever heavier and I was thankful to be spared the wrist ache than resulted from low speed work on the Yamaha.
Not surprisingly, given its paucity of power, the CB was a bit lost on fast roads. It had the ability to cruise at 70 to 80mph, come what may, but was often reluctant to put 90mph on the clock in unfavourable conditions. Rather too much work on the not particularly smooth six speed gearbox was needed to maintain 90mph for any length of time. In neutral conditions it was possible to do 95mph, but a bit of a following wind or slight downwards gradient was needed to crack the ton. A couple of times I cursed the machine for its lack of acceleration from 80mph when on the motorway. There are circumstances where a violent burst of power can safely put you out of the path of insane cagers.
Producing nearly twice the power and weighing over 50lbs less at 320lbs, this was not a problem the RD350 had. It would accelerate hard all the way up to 115mph, putting an extra 10mph on the clock under kind conditions. It could not be called relaxed touring, though, the chassis always felt as nervous as the motor and the thin fairing vibrated so much that it wore through the plastic at a couple of mounting points.
The Honda had a more comfortable seat and riding position, though that would not be the case if it were capable of the Yam's turn of speed, when the slight racing crouch of the RD would win out. Two strokes are supposed to be simple, but the RD defies that logic. Induction is aided by reed valves, the exhaust features powervalves and the top end is watercooled. Suddenly, the four stroke twin Honda begins to look the less complex.
Whereas the Honda suffers from its cam and balance chains, the Yamaha has to put up with seizing powervalves and short lived pistons (as little as 15000 miles). The stroker is the simpler to maintain, with its total loss oil system and lack of valve clearance adjustments, although like most strokers, spark plugs can need replacement after just 2000 miles! Both manufacturers have been making twins since the sixties, but whereas the Yamaha has gained power, lost weight and become more durable, the CB350S would have trouble matching some of Honda's better 250s.
The CB motor is yet another variant on the Superdream theme, with the same cheap and nasty looking engine cases and peculiar three valve head which appears to offer no benefits on the road over either the older two valve designs or later four valvers. If it had been any good it would have been adopted by the rest of the Honda range.
Neither of these machines was very old or done more than 10, 000 miles when I bought them. I was therefore pretty miffed come the first autumn rains to find that corrosion was breaking out on both machines. I'd settled nicely enough into using the Honda in the week and the Yamaha for long distance stuff over the weekend. My mates all rode fast bikes and it would have been ridiculous trying to keep up with them on the Honda. So both bikes were getting as wet and cold as their rider.
The CB was the first to show signs of wear and tear, with paint falling off the frame, rust blotching the swinging arm and the exhaust being reduced to the dark red finish of ferrous oxide. I'm not a completely useless bugger, so it was out with the sandpaper and paint cans. Blow me if the damn thing didn't throw off all the new paint and start rusting again within a matter of weeks.
About the only good thing about the amount of oil the Yamaha spews out is that it keeps the silencers in good nick. The frame was more resistant to corrosion than the Honda's, it took a whole winter for patches of rust to break out. The paint on the petrol tank was poor, though, peeling off where a few drops of petrol spilled.
Neither bike is too hard on consumables, the Honda being the better by the odd thousand miles and not being so sensitive to worn tyres. They both have too many discs with calipers that are ferociously attacked by winter salt. I've never kept notes, so can't be too precise - figure 12 to 15000 miles for chains, pads and tyres. The only major difference in consumables is that the Honda doesn't need a set of sprockets every time the chain is changed.
Another big difference is fuel, the Honda managing 50 to 62mpg, whilst the poor old Yamaha does 30 to 45mpg. I've averaged 55mpg on the Honda and slightly better than 35mpg on the Yam. This difference is understandable as I tend to thrash the RD and ride the Honda in a sensible manner. Neither bike could be called economical, though, I think that the fuel consumption of modern bikes is way over the top. Given the Honda's mild nature, I would have expected 80-90mpg!
As mentioned, the best description I can manage of the RD's chassis is nervous. It doesn't wobble in a big way, like some older strokers (who mentioned H1's?), just a bit of handlebar twitching under acceleration and a slight amount of weaving. The rear shock is still OE despite the 32000 miles that are on the clock, which may explain a lot as they often lose damping before the guarantee expires and were never first rate even when straight from the crate.
One up to the Honda, its twin shock arrangement feels tauter and hasn't needed any attention( with 29000 miles done), whereas I have had to put in two sets of swinging arm bearings and one set of linkage bearings on the RD. Not an easy job as there was a lack of grease, leading to everything seizing in position. If I'd left it any longer I would have had to replace the shafts as well.
The seals in both sets of forks are still there, but both front ends feel less taut than they should - harsh use of the powerful brakes on either leads to some wild pogo-stick actions at low speeds. I've still got both bikes, they run okay but look rather tatty. The Honda runs better than the Yamaha, which has become very temperamental of late, often refusing to start and misfiring in the wet.
I've not impressed with the longevity of either. The Yam is good for disipating the blues and the Honda is fine for slogging into work. It's possible to tour on the CB but a bit boring if you do any motorway work. They will both have to go soon, I want to try a big four next.
Alan Lewis