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Petrol cans, Lumiweld, and lunatics

by Jacqueline Bickerstaff

I recently rode along the A45 heading for Harwich, which provided an opportunity to visit Hon. Editor Andrew. He quickly filled Stowmarket with one-way streets and moved his house into one with 'No Entry' signs at both ends, but to no avail. I had ridden my 1909 Triumph far enough for one day, thank you, and was going to blag somewhere to put my sleeping bag for the night, notwithstanding such subtle hints. Being a good Editor, he extracted a promise of some words for the magazine in return.

I haven't been doing much on the cyclemotor front recently, due to a lunar induced desire to ride other silly two-wheelers (such as the above mentioned Triumph, which was en-route to EstoniaŚlook in the USSR if your Atlas isn't up to date), and I must sheepishly admit that the Firefly has hung on the wall since returning from the 'Team Firefly' trip to the FIM rally in 1991. It had returned from that trip with the cracked carburettor and cracked carb manifold finally giving up their mutual support act and only judicious use of wire holding them in sufficiently close proximity to vaguely work. This year's Vincent Club 'Riders Rally' was to be held quite near to my home and even by my lethargic standards it was time to fix the problem and put it back on the road in order to attend. With nothing much to lose I decided to attack the bits with 'Lumiweld' the low temperature aluminium welding stick which is widely advertised (and copied). I don't know what alloys cyclemotor carbs are made of, but it looks more aluminium based than the bigger Amals whose zinc-based material can be welded by Lumiweld experts but turn rapidly into blobs-on-the-carpet for the rest of us. I had one successful job behind me - look at the ally hinge on PUB next time you see it, repaired in desperation when it cracked in half some years ago - it isn't a flush and invisible joint but it has held. Smaller jobs are actually harder, and differences in section between the parts to join also make life harder as they do with all forms of welding, because the lighter item melts before the heavier one gets hot. Trying to repair my two bits and get them to fit together again was well beyond me, so instead I simply welded the carb to its stub permanently! The technique is to get the stick material to melt over the join, without applying enough heat to melt the components. A Camping Gaz blow lamp will do the job, and with ally there is a reasonable difference in melting points to do it without melting the items themselves (but they may soften and need support - more in fact than I gave mine); zinc based Mazac items melt about ½ degree above the stick material and do require skill and good control of the heat source. Joining, however, is inhibited by oxide films on the joint surfaces, so when the puddle is formed a stainless steel rod is dipped in and used as a scraper, slag accumulates on the puddle surface. After blowing some of my manifold away, but managing to re-fill the hole, I succeeded in joining the two bits. As extra security, and to cover any small air leaks, I have taped over the join too, and it has got the bike running again. Since there are a lot of cracked and damaged Amal 308 carbs about maybe this will encourage someone else to try repairs.

Apart from the air filter falling off and getting lost (probably didn't matter since the Firefly is bottom bracket mounted and I expect I ran over the fragile thing), the contraption was still in running order after the rally. Monday was D-Day celebration, and since my engine is fitted to a paratrooper's folding BSA I decided to go to work on it. The original Vincent tank will not fit this frame, so I have a little 1-litre tank made from an oilcan with soldered on fittings. Thus, I carry a separate can in a pannier in which to mix the petrol and oil, and from which to dispense litres as required. In Northampton I needed to fill it - no dice. From her cubby-hole the attendant saw (apparently) a cyclist filling a can which she didn't think was a BS approved plastic item so no joy. She switched the pump off and was not open to discussion. Fortunately, there was another petrol station within walking distance at which I filled up from the far side of the furthest pump from the attendant's hut. But be warned, Health & Safety rules - O.K.

Now the Firefly is back on the road I had hoped to attend more meets, but so far, they have all clashed with committee work or holidays, and it is languishing on the garage wall again. No Brownie points for me.


First published - October 1994


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