In my efforts to match up a "pair" of carburettors I have come into posession of 2 carbs that are, on the face of things, physically the same. The only obvious differences are: the thread sizes on the throttle cable ferrule, and the hard stamping. One is stamped: 12 66. 389 236, and the other is stamped: 12 66 689 236. The two on the bike are stamped:389 /71 and 389 /002.
In single sylable words can anyone tell me what I am looking at and whether any of the four carburettors could, or should, work in tandem.
Bacon's Norton Twins Restoration to the rescue....
389/236 was, according to Mr. B, from a 1966 Export Atlas. 669/236 also. Being the left and right handed carbs in the pair. He doesn't say anything about the '12 66' but they must obviously be the date of manufacture.
389/71 from 1961-63 twin carb 99.
389/002 is not listed.
But the numbers were only used to assist in factory assembly. It's up to you what settings you use.