Little Wing
Last month, Stu Thomson learned all about Aermacchi’s ‘Wing’ series of singles. This time he tracks down a 1959 Ala Azzurra and starts to prep it for flight…
Ihad always hankered after an Aermacchi and early in my search went to view a 1970s Harley Sprint – a development of the original Aermacchi single, built in Italy for the American market – but when I saw it I could not believe how disjointed and awkward it looked. The cylinder had the later, allcovering head cover, longer forks, peanut tank, high bars, mismatched seat and
mudguards, all apparently standard. It looked like someone had designed it after a bad trip, as they used to say in the 60s.
Then I found an Aermacchi Blue Wing, the Ala Azzurra. It just looked right to my eyes. It was advertised as an Ala Verde, the sports model, but I could tell from the photos and a bit of research that the model was either a Blue or a White Wing. These were the touring models with same frame but a less stressed motor than the sports models, and a different petrol tank shape with low touring handlebars. It turned out to be a Blue Wing 250, confirmed by the engine and frame numbers, with a UK V5C. The negotiated cost was much less than a Green Wing would have been.
As a 1959/60 model, the Blue Wing was an early version with a smaller rear brake drum, no rear mudguard stay and no hint of HarleyDavidson. The engine casings and toolboxes only have the Aermacchi logo, not like the later bikes which developed Aermacchi / Harley-Davidson badges, and then AMF Harley logos.
I found maintenance and parts manuals on the rpw.it website covering the Aermacchi range, a good starting point for any potential owner. A period advert for the Ala Azzurra gave me a good idea of the paint scheme for the late 50s and early 60s models – more searching turned up a picture of a similar Ala Azzurra and a petrol tank with its original paintwork, which finally confirmed the design of the white flashes.
The Blue Wing is very small compared to similar capacity bikes of the period like the Guzzi Lodola and MV Agusta 175s. Its small 17” wheels make it about the same size physically as a Gilera 98 but with a much more robust frame, forks and swinging arm.
The Aermacchi is some 25kg heavier at 115kg than the 90kg Gilera. My little Gilera is pretty quick for its capacity, but with a 250 engine it would be well overpowered in the frame / forks dept.
My first job was to see if my Blue Wing actually ran. I checked the oil and it was clean, which was a good start. With a decent battery connected, the spark was good. The carb looked OK but I gave it a full clean anyway. Compression was a bit weak, and when kicked over the engine fired once and banged from the exhaust. I decided to whip off the head and barrel for a check. Initially all seemed to be in excellent condition, but when I checked the ring gap I spotted the first problem…
The bore looked good with virtually no wear and no ridge close to the top. The piston was a 0.6mm oversize, but when I checked the ring gaps they were about 3mm when they should be 0.2/0.3mm for an air-cooled engine of this size in good condition. The head gasket was missing; it should have been a simple copper ring. I surmised that a previous owner either put it back together quickly, or tried to get a bit more performance out of the bike. There is no way wear could have occurred to 3mm on the rings so presumably the bore has been machined to suit the piston – but the rings are standard. It looks like a rush job to get it back together quickly to sell it. The previous owner had bought it from an auction: buyer beware, as they say!
I needed to find the correct rings, or a slightly more oversize piston with rings and rebore the cylinder. First I tried new rings from thekingofpiston.com in Italy. These gave a ring gap of approx. 0.4mm; not perfect but good enough to see if the engine would run. No joy initially, but there was now very good compression and there was a bang from the exhaust when I tried to start it. So I wondered if the timing was out. When I checked the cam position for the points opening it was actually 180 degrees wrong – the points were opening on the exhaust stroke!
I moved the auto-advance cam on the ignition through 180 degrees and the bike fired second kick. Result! It ran quite well and even ticked over reliably when warm. Importantly, there were no nasty knocks or noises, just some tappet noise (but not as loud as my Triumph Tiger 100). Someone had fitted the auto-advance cam incorrectly, which in theory should not be possible as there is an offset in the plate key. However, when things start to wear it can be done – as here.
The ignition light went out when the engine started, indicating that the dynamo was working. When charge from the dynamo is detected by the voltage regulator, it earths the contact to the bulb.
Next I needed to look inside the clutch casing. This revealed a substantial primary drive with helical cut teeth. Unsurprisingly, it
had been worked on before, looking at the tabs on the nuts. Part of the clutch actuation mechanism was missing; the part on the end with a thrust bearing. I made a new one from EN24T and replaced the ball thrust bearing with one I fabricated from phosphor bronze.
Spares for these machines aren’t as hard to come by as for some other Italian bikes of their time. The arrangement between Aermacchi and Harley meant that there were plenty of spares for the American market. Frame and cycle parts can be an issue as they changed the design pretty quickly for the Sprint variants, but some American Harley dealers still have early Aermacchi stock for engine components; pistons, rings, clutch plates, etc, which are similar if not the same as the Italian ones. You can get NOS pistons with rings for as little as £50 delivered, for example. The Veglia (or ‘Vaguelia’ due to its inaccuracy) speedo is the same as one on an early 1950s Lambretta 125, so bezels and lenses are easy to obtain from Lambretta spares suppliers – and in stainless steel, no less. Used spares from Italy tend to be exorbitantly priced, however.
With the Blue Wing running, the question arose of whether to fully rebuild it or fix what was broken. The wiring looked a bit brittle and burned, so that needed renewing. The cables were all worn, and all the paint looked tatty and thin. On close inspection, the chrome on the wheels was non-existent. Silencers and exhaust pipes are available from Brezzi Samuele Collezionismo or Moto Storiche Italiane, so no problem there. 17” alloy rims are available from BEB Mecchanica for a reasonable price; rims and stainless spokes came to around £280 for both wheels. I made a jig a few years ago and now feel pretty confident about wheel building. It’s really easy with new rims and new spokes as long as you know the correct offsets. The most important skill is patience!
The brakes were relined for £40 by Villiers Services, who do a good job and provide linings to suit your requirements, road or race. With that job completed and with the engine running, in theory I could ride the Aermacchi… but I finally decided that a bike of this quality warranted a decent rebuild. It would be worth bringing it back to its former glory – so which colour should I paint the frame and cycle parts?
Yorvik Engineering Services, my favourite friendly powder-coaters came up with a good match. RAL3002 Carmine Red is available in both powder coat and 2K paint and looked good compared to the original Rosso Sport Red. The great thing about RAL colours is that they are universally available in just about all paints, great for touching up the inevitable
damage from daily use.
Overall, the Blue Wing’s cycle parts were in good condition; it looks to have been cherished for much of its early life. They showed minimal rust and, importantly, hadn’t been bashed or crashed. The rear mudguard has extra strengthening where the seat fixing and frame locates. Overall the parts components are thicker gauge material than most of the small capacity Italian machines I’ve rebuilt – manufactured with more care.
A few things were missing – including the side panels and speedo drive – and a rather dodgy chainguard from some other bike was fitted. Replacement side panels came from a UK breaker, advertised as being for a Harley Sprint but they were adapted to suit the Aermacchi with a little work. The speedo drive, chainguard and an inner alloy rear drive sprocket guard all came from the USA for around $25 each. I’d anticipated these would be very difficult to obtain: just shows how wrong you can be!
The forks are a conventional design and weren’t very worn or bent. The bushes were good, so they just needed new double seals and 15W fork oil. If the speedo is to be believed then this bike has only covered 10,000km – the generally good condition of its components are witness to this.
As I am not a great fan of chrome I decided to make front fork covers from alloy tube. I did this with my Morini, and they look pretty good when fitted. The tube was about £10 to buy and took a couple of hours each in the workshop to make. No complicated threads to machine because the tubes are held in place by the oil seal holders; they’re really just for show, to make the forks look finished.