DUCATI DAYTONA
Pip Higham restores a Duke.
When I was a lad, I bought a crashed Ariel Leader from one-legged, briar-pipe smoking Billy Briggs (Motorcycles) in Salford for 40 quid. I straightened out the forks and fiddled around with it, but as my 16th birthday approached I could see my dad getting a bit edgy. He thought I was going to go and run into the first solid object I encountered on two wheels. On the first Saturday after my birthday (and still with a full complement of working limbs) he dragged me to King’s on Stretford Road to look at NEW bikes! There were Hondas, Yams and rather a long line of Ducatis. I was quite taken with the little Dukes and at just over £200 they were very appealing but I eventually succumbed to the meticulous Honda-ness of the CB160. Its little blue tool roll and sweet controls were hard to resist: it was so damn cute. I can also remember at the end of the row of shiny bronze and chrome (thin chrome, mind) Ducati Elites were a couple of Daytonas, with sit-up bars, looking undeniably smart, but all I wanted to do was fiddle with the switches on the 160 and weigh up how long it would take me to whip out the baffles. Moving on a few years and I happened across a black Daytona bearing the registration LEV 80C. The history with it said it had been thrashed by several bike journos who’d tested it for Motor Cycle and Motorcycle Mechanics, back in the day. I had to buy it and it’s now back to exactly as it was intended to be, but how did I make it so?
Rejuvenating LEV 80C
The Daytona was in a bit of a mess but solid and complete. Critically all the sheet metal was good, fuel tank and guards were sublime, but the paint was shot and there were odd patches of ferric oxide but nothing that a gentle dose of glass bead followed by the careful application of some good quality zinc-rich primer wouldn’t sort. There were signs that the motor had been the subject of significant work so before I stripped it, I ran it down the road very gingerly. All went well through the gears but then a mysterious neutral arrived between third and fourth. Subsequently (and without noise, protest or any other indication) the gearbox stopped changing at all, except when it felt like it. When I tore the motor down, the gearbox fault was no more than a selector fork that was present and
unharmed, just not engaged with the slot in its intended gear. It was clear that I had to check the entire engine given the apparent nature of past repair work. As there’s no fool like an old fool (and I certainly tick both of those boxes) I didn’t stop when I got to the crank, I took that apart too. The Ducati uses a neat Newtonian trick to keep the oil in good shape. Before feeding the critical big-end bearing the oil passes into the off-side flywheel where any heavy deposits are flung outwards, courtesy of gravity and a bit of centripetal force, into the delightfully named ‘sludge trap’. This is all well and good but if the aforementioned gets full of sludge then the oil no longer floweth and the big-end ceases to be a bearing and turns into a sort of mangled, metallic art installation. Not good if you happen to be enjoying the twisty bits up the Cat And Fiddle on a Saturday afternoon. Brandishing my favourite bottle brush and a tub of paraffin I got all the internal oilways squeaky clean and was able to rebuild the crank with minimal expenditure. Some may say this is false economy, but the OEM bits fitted back then were superb, and there wasn’t a trace of wear or rust etching so I figure it’ll do another 25,000 miles. To allay any fears about bearing deterioration I did replace both main bearings, plus the outrigger bearing located in the clutch cover (nice touch that, an extra ball bearing located in the outer cover, just the ticket to stop the crank shuffling about at times of stress) and all other ball bearings with top quality Koyo or SKF items. While inspecting the bearing that controls the top of the bevel drive assembly, a piece of it simply fell off! I’d never ever seen a bearing fail like this before and it certainly came as a warning to me, that even if I wasn’t intending to change every internal bearing (I was) it is absolutely essential that great care is taken to clean and inspect every moving part at this stage of a rebuild. There is an order of play which cannot be circumvented when you rebuild this little jewel of an engine and it goes a bit like this: the end float on the crank has to be measured and the crank shimmed accordingly to zero clearance. At this stage the bottom-end of the engine can be assembled. One note of caution here: if the short vertical bevel isn’t located before the crank is fitted it can’t be put in after, this means that the cases would need to be split again! Then the lower bevel gear pair can be shimmed for perfect mesh and engagement.
At this stage any repairs to the head need to be completed which includes changing the two ball bearings that support the camshaft. I changed both valve guides and John at Headshop (UK) in Warrington worked his magic on the valves and seats. Please don’t ask me what grade of valve grinding compound to use, throw it in the bin! Do you really believe that modern engine producers grind valves in? They don’t. Correctly prepped valves and seats bed in within seconds and don’t leak! I’ve converted a couple of my smaller Ducatis to coil springs but in the interest of originality I retained the original ‘hairpins’ for the Daytona. With the cam in place it’s time to shim the top bevels. Always approach this from a position of excessive play and carefully select shims to reduce the clearance to minimal while allowing the bevel shaft to spin freely with no trace of binding. A point often missed at this stage is that the double row, self aligning bearing that sits at the upper end of the long bevel shaft must be clamped firmly in the head by the aluminium bevel enclosure housing. That sounds like it should be a doddle but the housing must also seal to the head while clamping the bearing outer. This ‘dual duty’ is quite tricky to achieve and requires patience, many shims and several different thicknesses of gasket material. All-in-all this one operation is definitely the most critical and frequently the least accomplished task in the re-assembly journey. If the housing stands off too far it will leak oil immediately. If the bearing isn’t nicely pinched up it will fret in its housing, and as it frets the bevel pair above become very agitated and will wear out or fail very quickly. With the handy dots lined up, the head, with bevel shaft set in place, is popped in. The shaft slides into the ground ‘Oldham’ coupling sleeve which in turn is retained in position by a circlip above and below. In truth the engine, although demanding, is extremely simple to work on. Anybody new to the little singles will recognise odd parts of the design which can be found on many other engines, mainly those produced on a different continent. A cross section of the crank/ con rod/combustion chamber/valve configuration of the Ducati 175 (from which the basic design later developed into the 200cc Elite and then 250cc Daytona and Mach 1) by a strange coincidence, displays a remarkable similarity to Suzuki’s GS750. Imitation may be the sincerest form of flattery but I’m not sure if Fabio Taglioni would have shared that sentiment! I’ve concentrated mainly on the beating heart of the Daytona for good reason: the cycle parts are very simple to sort, with care. The frame is a masterpiece of simplicity with the 45mm spine creating a flex-free connection between the steering head and the swingarm pivot. Everything is fixed in place with standard 6mm and 8mm bolts, the exceptions are the tank mountings, kick-start and horn fittings which utilise 8 x 1mm thread configuration as opposed to the more common 8 x 1.25mm. I rebuilt the wheels with plated spokes and chrome rims as nature intended, fitted skinny tyres, new wheel bearings and a fresh chain and sprocket set. Naturally everything was meticulously cleaned and, where necessary, re-plated. Sadly I can’t find a source of correct cadmium re-plating, something to do with environmental correctness, so it has to be zinc which, it has to be said, is pretty close.
There are many stories of tragic engine failure on early Ducatis; in my experience they occur for one of two reasons: deterioration of the litre or so of oil in the sump and lack of owner ability, or LOA. The oil can get polluted by fuel going by the fuel tap and running into the engine. Simple fix: keep an eye on the tap(s) and change the oil frequently (it’s only a litre) otherwise the oil-tight nature and amazing reliability of the creature leave the oil level constant for many months, then people get lazy and don’t change the oil, ditto. So just change it regularly. ‘LOA’ is a different matter. Here’s the scenario: poor little bike is deprived of TLC for an extended period, hapless owner then tries to remove the plug but strips the thread in the head, he then removes the head but fails to understand the slightly quirky procedure required to set the valve timing on reassembly. At this point a couple of mates with divergent ideas on engine assembly pitch up and the poor bike never runs again. The top-end of a single-cylinder Ducati could be removed with minimal tools by anyone in a Naples back street and replaced in minutes: there’s no head gasket and only a couple of other simple gaskets that frequently remain serviceable. The trick is to understand the mind-set of Fabio Taglioni, the inspired engineer who created it. We’ll look at him next month!
Riding LEV 80C
On the road it’s spot on. It’s slow but retains the trademark Ducati handling; you don’t need to think about how to approach a corner, the bike takes care of all that thanks to the large diameter spine frame. The combination of light weight, at about 110kg, and modest output provide a lovely lazy riding experience. The brakes won’t stand it on its nose but they’re plenty powerful enough, 180mm diameter at the front and 160 at the rear with big wide shoes were designed to deal with Il Passo Della Futa, or the steep hills of Naples, so they’re just fine and won’t fade. The gear ratios suit the power delivery perfectly, possibly due to the fact that Ducati fitted a pretty substantial brass flywheel which doubles up as the generator rotor. From idle upwards the motor pulls sweetly well into the mid-range; it then runs out of puff a bit, probably due to the dinky 24mm Dellorto UB carb. While the Mach 1 was the Daytona’s naughty brother, the Daytona was happier going to the shops or a tea room perhaps. Of course I didn’t buy LEV to go fast on, I bought it because it reminded me of fun and simplicity. It has those in buckets, but it also possesses a purity of line and quality that still amaze me after 50 years. The Mach 1 was definitely an iconic machine but for a Sunday afternoon ride I’ll take the Daytona every time, it’s pure magic.