70’s six pack, Honda CBX1000Z
This stunning example was Kevin Murphy’s first real attempt at a restoration and what a job he made of it, being as near perfect as possible while still remaining a practical day-to-day ride too.
Owner profile
Kevin Murphy is a Nottingham based development manager, currently working on environmentally friendly cooling systems for the telecom industry. He rides a VFR800 on his daily commute and his garage boasts a bevy of interesting projects but a mint silver CBX1000Z dominates the proceedings as indeed will a Spondon framed version in the next few months, as that too nears completion.
Kevin’s involvement with the CBX came in 2002 following a visit to the Stafford classis show, he went to assess the classic market and to see what machine would suit him best. The big six soon grabbed Kevin’s attention and he knew it was the bike for him and started the hunt for a tidy example. A search on eBay soon found Pro-link example, the later monoshock version aimed at giving the type a more touring stance and hopefully gain favour in the USA, a country that missed the point behind the original design and subsequent sales proved to be poor. Still the Pro-link weighed in a good deal cheaper than the iconic Z and A models so it appeared to be a good buy, however once in the workshop several parts turned out to be beyond repair and a new frame was deemed necessary. Kevin advertised for a frame and one call completely out of the blue actually turned out to be a complete bike, albeit totally stripped, and at the right price too. The parts lay boxed and apparently complete having been stripped some 15 years earlier with the intention of a nut and bolt restoration. Several new parts had been bought in anticipation of the complete rebuild so many shiny new panels and body parts sat waiting to go. Kevin took a big leap of faith and bought the many boxes, loading up the car to shift this supposedly complete machine from its Rotherham home back to Nottingham so the work could start.
Once spread out Kevin could see the majority of the bike was certainly present but not having stripped it himself he was unaware were most of it went and in which order. The genuine manual offered little help when it came to this sort of detail and it would have proved invaluable to have recorded the tear down is some way, it took much longer to reassemble and many hours looking at other complete machines to see where wiring was routed to get it right. Another problem caused by one person taking apart and another putting back together was found when it came time t run the bike for the first time, it started fine but had a problem with fuelling in the midrange. It turned out that the previous owner had started to strip the crabs removing the secondary main jets before quitting and putting the instruments back together without these important items. Of course Kevin was unaware of this until he went looking for a cause of the fuelling problem and found a small tin with the six jets in languishing in the box of left over parts. Another bit of bad parts management many years before Kevin took possession of the project, saw the brakes stripped and left to the open air, the rubber expanded over time and completely seized many of the components, this took much time to overcome and could have been completely avoided if the brakes had been left in tact until the time came to take the job on restoring them.
The frame was expertly stripped and recoated by Redditch shot blasting, a company well known for their high quality work with motorcycle components, the finish being tough and as smooth as can be imagined. While this was away being attended to Kevin began work on the awesome looking engine, the bottom end, once cleaned, slotting together relatively easily into the repainted casings. The problems really began when it became time to tackle the top end and Kevin admits to having been caught out by the complexity of this task, there being six of everything, all requiring assembling to exact tolerances and settings. Measuring the 24 valves showed there to be some wear, mainly on the inlet side of things, so SEP in Kegworth, just up the road from Kevin, were elected to carry out a full overhaul of the cylinder head and its workings. New valves were fitted, and the seats re-cut to provide the perfect setting for them, enabling the head to be slotted into place atop the six pistons ready for the word to go once in the chassis.
Kevin considers himself to be lucky as the initial gamble paid off, all of the parts the pervious owner said was in the many boxes actually were so little was needed over and above the cost of the repairs to get the bike back to its stunning condition. Many parts are now virtually extinct, major items like the 6-2 exhaust is so rare the only option would have been to fit an after market system had these been missing or damaged, and with it seriously compromising a restoration back to the bikes original specification. Once back together and running as it should it soon became noticeable that the front end was far too soft, something that the original bike suffered from when new but this was even worse, Hagon products had the answer with a set of progressive springs for the forks and the idea to use 10w oil, instead of the original 8w, these two mods completely sorting out the loose feel of the front end.
The original Pro-link CBX, that proved to be too costly to repair, was stripped and the majority sold off for spares to fund the build of the silver Z, Kevin did keep the engine however and a brand new Spondon alloy tube chassis sits in the front room awaiting the fitting of this and the creation of a real CBX special.
The CBX owners club
Founded sixteen years ago and now has nearly 600 members around the world, including Japan. The club produces a quarterly full-colour 50 page magazine as well as providing its own CBX insurance scheme where a bike can be covered fully comp for around £100.00, including an agreed value and unlimited mileage. Experts within the clubs ranks can provide unlimited, free technical advice, as well as providing links to other CBX owners worldwide via the extensive website. Often the club can negotiate discounts on spares and services useful to any owner looking to restore or repair their CBX, and there is also the facility were selected special tools can be loaned to members including the free use of 6-cylinder vacuum gauges enabling the carburettors to be synchronised to perfection.
Like most clubs there is also rallies around the UK and the odd foray into Europe too while the club has stands, where members encouraged to show their bikes, at all of the main classic bike shows throughout the season.
Mel Watkins is the man to talk to
CBX Owners club tel 01745 827026
www.ukcbxclub.com
Problems encountered:
1: The brake system proved to be a nightmare having been partially stripped and left dry for a decade and a half
2: Because the strip had been done by others Kevin had a hard time fining were certain parts went or were situated on the frame
3: Under estimated the extent of the complexity found within the cylinder head
4: Although the carbs were assembled the previous owner had left out some important components causing much confusion on reassembly until the error was spotted
5: Fork springs although looking fine were tired and needed replacing
Info/Contacts:
CBX Owners club, tel 01745 827 026
www.ukcbxclub.com
SEP, tel 01509 673 295
www.sep-kegworth.co.uk
David Silver spares, tel 01728 833 020
www.davidsilverspares.co.uk
Redditch Shot Blasting Co ltd, tel 01527 529 659
www.redditchshotblasting.co.uk
Hagons, tel 0208 5026 222
www.hagon-shocks.co.uk
Engine/Transmission
- Type Air-cooled, four-stroke, transverse six-cylinder. DOHC, 4 valves per cylinder
- Capacity – 1047cc
- Bore x stroke – 64.5 x 53.4mm (2.52 x 2.40 inches)
- Compression ratio – 9.3:1
- Fuel System – 6 x 28mm Keihin CV
- Primary/final drive – 2.268:1, 2.333:1
- Clutch/gearbox – wet clutch, 5-speed, chain final drive
- Electrics – 12v 18AH Electronic ignition
Chassis
- Frame – tubular steel Diamond
- Front suspension – 35mm air-assisted telescopic forks
- Rear suspension – steel swing-arm with twin oil damped shocks
- Brakes front/rear – 2 x 276mm discs single-piston floating-calipers, 296mm disc single-piston floating-caliper
- Wheels front/rear – alloy Comstar 3.50 x 19, 4.25 x 18 inches
- Tyres front/rear – 100/90 x 19, 120/80 x 18 Bridgestone BT45
Dimensions
- Dry weight – 247kg (544lb)
- Wheelbase – 1495mm (58.86inches)
- Seat height – 810mm (31.9inches)
- Fuel capacity – 20litres (4.4gals)
Performance
- Top speed – 130mph
- Max power – 105bhp@9000rpm
- Fuel consumption (claimed) – 39 mpg
- Price new – £2750.00 inc vat (1979)
Kevin’s top tips for CBX restoration
Record every step of the strip down with a digital camera, or even by a simple sketch, as this information will be invaluable later
Carry out extensive research on your intended project before parting with any cash
Avoid boxes of parts that masquerade as complete bikes unless the price is irresistible, it worked this time but was a heart racing thing to do
Try to plan for the worst-case scenario when buying
Whenever possible join the owners club well in advance of parting with serious cash
Try to buy within the club too, most members know each other’s machines and can offer advice on value etc
Watch prices, and check with a dealer on the correct cost before diving in on eBay
It can often prove more cost effective to buy new fittings than risk losing them while being replated etc
Honda CBX1000 Gallery
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