New plugs did not produce a spark. The points were so worn they hardly moved when the cam lobe hit them. New points produced a weak spark. A new condensor got the spark a nice deep blue colour. I adjusted the valves, put in some new oil and gave the camchain tensioner a tweak. The twin cylinder OHC engines are dead simple to work on with the aid of a Haynes manual.
There wasn't an electric start, so I had to spend half an hour on the kickstart. Despite some encouraging noises the motor was unwilling to burst into life. I took out the plugs, heated them on the gas stove and shoved them back in. Handling red hot plugs is not much fun and | nearly cross-threaded one in the cylinder head. Second kick we were in business.
Took a while to warm up but then ticked over OK and pulled nicely during a quick blast up the lane. The motor was relatively quiet; I'd heard nearly new GPz305s that made more of a racket. The chassis was blurred with rust but otherwise surprisingly sound. The tyres and chain were far from needing replacement, so all I had to do was remove the corrosion and touch up the paint. The MOT certificate wasn’t a problem despite the lack of baffles in the much patched silencers.
The CD looks less than appealing at first glance, with a pressed steel frame and very large mudguards. The angled forward cylinders do make it look quite modern from certain angles but the dull grey paint put it firmly in the commuter camp. I was therefore somewhat surprised to find that the old heap burnt off a TZR125, making the bemused rider look like he riding a fifty.
As the speedo didn’t work I never knew exactly how fast the horrible Honda went. But flat out motorway work revealed that the bike could keep up with the slow lane, occasionally needing to burst into the middle lane to overtake something like a Metro driven by some old dame. At least 75mph, then, maybe as much as 80mph. The Honda wallowed slightly flat out but it never seemed to be dangerous, despite cheapo tyres and suspension that was 25 years old.
One problem with the suspension was that there was not much movement, each and every bump was fed through to my backside and arms. For this reason, the bike was more enjoyable flat-out on the motorway than being thrown around the back roads. There was an annoying tendency to run wide through bends and to dig the centrestand into the tarmac when leaned over at extreme angles. The latter would attempt to flick the bike off the road, but was easily remedied with a flick of the buttocks and modified cornering line.
In town the CD was narrow, nimble and showed a surprising turn of acceleration in races with enraged cagers. The only problem was the four speed gearbox, which had large gaps between ratios and was dead easy to throw into false neutrals. But there was a lot of feel in the box and after a while I able to successfully work my way through the gears; I was used to old hacks with temperamental motors.
After a month I was impressed enough to persuade a mate with a spray gun to do a quick respray in black. He only charged me for the paint, the bike ended up looking rather good, only spoilt by rusty rims and exhaust. Both were treated to a wire brushing and a dose of matt black paint, which if not exactly an immaculate finish was a great improvement.
The bike needed loads of fuel poured in the tank (I guess 50-60 mpg) and continuous topping up of the sump. A small amount of oil was burnt out of the exhaust and a little leaked out of the gearbox seal and cylinder head gasket. The engine bolts looked so virgin and so corroded that I could believe the engine had never been touched internally by human hand. If that was so, it speaks volumes about how tough they used to make old Hondas.
In six months I must have done about 5000 miles, buzzing around at weekends and commuting to work in the week. The only problem I had with the CD was that fuel would piss out of the single carb every so often. Easily fixed by playing around with the float height. Oh, and one of the cylinders would cut out for no apparent reason and then clear up just as suddenly.
I sold the bike for £275 as I'd found a cheap CB400/4. The day before the new owner turned up I went for a final thrash on the CD, with a friend on the 400. Up this nearly deserted dual carriageway we screamed. I had to thrash the Honda in third to keep the bigger Honda in sight. With my head down on the clock, I held the throttle wide open, the engine surprising me by continuing to rev. There’s no rev counter so the only way I knew I was in the red was the way the whole bike blurred beneath me from the vibes. It was usually rather smooth despite having pistons that moved up and down in unison.
When the vibes became unbearable I changed up to fourth, then moved my feet to the pillion pegs (themselves on the swinging arm). I was one with the machine, the throttle still open, the bike ever so slowly gaining speed. With the heavy dose of vibes once again afflicting the chassis, we drew abreast of the CB400/4 and then edged ahead. Once I was clear of the four, I rolled the throttle back, amazed at the little Honda and slightly sad to see it go. Admittedly, if I’d held the speed for any longer I would have suffered a bout of seasickness and probably blown the engine to pieces.
My mate on the CB never would admit what kind of speed he was doing when I overtook, but he looked at the CD in amazement when we came to a stop, demanding to know what I'd done to the motor. In the nineties the CD is just about adequate fare for modern roads, back in the sixties it must have been quite an amazing giant killer.
Buying and selling the CD175 goes to prove that it’s still possible to buy a bike for next to nothing, fix it up, have some fun and then sell it on at a nice profit.
Phil Goodwin