I finally have sussed what was wrong with the Amal 276 on the BSA: The float was set too high (mind you, straight from the maker, but that’s not much of an excuse). Imagine my excitement when I kicked the machine to life and it idled, stone cold–which it has never done. The carb was absolutely full of crud, too, which I suspect is the remains of the old cork fuel taps. (I’ll check it again in a couple hundred miles, but the tank itself was sealed when it was restored.)
Alas. Back from a short “victory” ride, I discovered I was leaving a trail of oil. The photo above shows why: the return line from the cylinder head decided enough was enough.
The offending piece broke right at the banjo fitting next to the tank (see photo below). The line has a flexible piece in it–perhaps a gesture to prevent this very thing from happening, though probably something related to assembly-line logistics. The piece is almost 60 years old, not bad innings, really, considered how vertical twins vibrate.
It turns out you cannot get this part new; it’s not even illustrated in the parts catalog. My theory is that the oil line assembly in its entirety, from cylinder head to union at the tank, is covered by the part number in the book, but only the upper part is illustrated. You can get the upper piece…perhaps because the lower line isn’t illustrated, the reproduction parts folk think it never existed. (British motorcycling is existential like that.)
I was able to scare a used line up from my friends at Raber’s Part Mart, and it should be here Tuesday. Hopefully it still has a few innings before it gives up the ghost!
I should note that, having now fixed the oil pipe, the bike no longer starts when hot…so I suspect my glee at the float height change was premature. When I can stand to look at the machine again I’ll swap the float height back and see if I can start it hot once more.
So very tempted to get a Mikuni and be done with the Amal, but no guarantees there, either.
Hi Roger. I just discovered this website and read about your oil line incident. The same thing happened to me about 30 years ago (I have a Golden Flash, also of the plunger type, but from 1956). I remedied it by drilling out the piece of pipe from the fitting, cleaning up the pipe end and solder (brazing) it in place in the fitting. It has not failed since then. By the way, on my A10 the oil line is not a return line from the cylinder head, but an oil feed line to the rockers, which feeds oil taken from the return line from the oil pump to the oil tank. Regards, Kaj