Getting better
By week two I'd clocked up about 500 kilometres and went to 30:1. The mixture was just too oily. It was now running better - starting first kick every time - and riding around the roads in the hills was a delight. These little bikes handle like they are running on rails. The brakes are excellent (for the period) and the electrics are all working fine. I fitted mine with period rubber and that may have been a mistake. When the budget permits I think I'll go over to some modern sticky tyres.

Week four and 1,000 kilometres. Changed to 50:1 and dropped the needles one notch. A different bike. Clean running, crisp acceleration but still a little more smoky than I would have expected.

What goes wrong and what to do about it
No restoration is without its downsides. This was no exception. The chain adjusters have to rate a mention. The Benelli item is a single sided design which bends instantly if you apply any force to it. Things such as tightening it up or even accelerating loosen the chain adjusters and your chain flaps around. We tried to fix the problem, but they are simply not up to it. Look for the adjusters from the Moto Guzzi TS 250 or the later Benellis. They obviously eventually became aware that the standard adjusters were terrible.

Watch out for the chainguard. Ours are fine but all our bikes had broken chainguard mounts on the swingarm from vibration. Keep an eye on this. Similarly, all bikes had the headstock steering stop broken off. There is bad welding wherever anything was tacked to the frame. The major welds are fine.

The stainless guards look great. The way Benelli has the chrome cable guides on each side of the front wheel is another of those "quality touches". The way the cable rattles in the guides will drive you crazy. Put some rubber in the guides to quieten it down.

If you are building a crankshaft get it done professionally. I've read that the original bikes had a batch of bearings that caused crank failure. The fellow doing my cranks replaced the bearings with high quality, race spec bearings. Make sure you do this.

Look for the roll pin in the gearbox. It is not up to the job. If your bike has done a few miles you'll see it there just managing to hold on. Just. I went up in size. Better than splitting the motor later for a 5c roll pin.

The chrome is hellishly expensive for this bike. However, a good chrome plater can take virtually destroyed silencers and bring them back to new. The metal quality on the silencers is very good. They can, if they go to a little trouble, even save those Silentium logos. Similarly, some platers won't want to do the flanged chrome rims. A good plater will make them look a million dollars but expect to pay for it. I went around to my plater and saw the work involved in polishing the flanged rim. It's worth it.

Summary

The three of us are enjoying our little Benellis immensely. They are more fun to ride than we imagined and are a great little sports lightweight. They attract attention wherever we go and even to non-motorcyclists the sight of a smoky two stroke is unusual enough these days. If you find one of these bikes in the back of a shed it is well worth the effort of bringing it back to life!