650ss carb

Sold with twin carbs and the No's would match from new. The guy is not straight. take a grand off for the things yiou can't see.

I doubt very much any 650SS left the factory with a single carb fitted but stand to be corrected. As for matching engine and frame numbers my understanding is they all left the factory since around 1946 with matching numbers, Nothing wrong with a single carb but kind of defeats the point of a 650SS in my book. The rich running may indicate difficult starting if set correctly or incorrect jetting etc. Nothing wrong with none matching numbers as long as it's reflected in the price. I would feel wary of what this seller is claiming and wait for something one of the members is selling on this site as Ive always found members represent their bikes honestly. Regards Paul.

The 650 was marketed as a single carb bike alongside the better known 650SS.  Might have had slightly softer cam. A single carb 650SS doesn't make sense. Not that it will matter much in practice nowadays. It might even be a nice bike for all I know. But just not 650SS. Check Bacon's books.  I'm sure others will have more info soon.

Its true that there were a few odd variants  ,  The 650 std , and even the 650Deluxe with bathtub!, however these are rare enough to be extinct .  Nothing wrong with a 650 with single carb and non matching no's . But past experience tells me to beware of sellers telling porkies. The value of the bike is much affected by the trust in the seller.

Of course the Mercury was a single carb 650.

I would be very wary of the vendor. He/she seems quite happy to bullshit. If about these things, what else? You want a knowledgeable sceptic to take a vey good look before considering any purchase.

There were only four periods when 650 Norton twins were produced with a single carb. The early Manxman models of 1960 and 1961, the 650 Standard and 650 de Luxe of 1961 & early 62 and the Mercury models of 1968 to 70.  The only possible exception to these would be a special batch of Manxman exported to the States in 1965. However, the chances are these were more of the Mk 2 Manxman version which were just the 650SS with high handlebars and a special paint job.

Possibly, a few single carb bikes were constructed for the military but this does not show as such in the records. By the beginning of 1963 and engine no 105***  only the twin carb bike was being produced. However, bear in mind that Bracebridge was about to close and there may have been unsold stock around the world.

So possibly this 650 for sale might have been old single carb stock but the engine and frame nos should match.

Hi John,  you say this SS has a single carb', my understanding of an SS is that it would have twins,  one with a chopped float chamber. Its always possible of course that a previous owner not being able to cope with twins changed over to a single  The engine and frame number also raises an issue, I had a near new 63 SS in 1965 and everything matched, a lovely machine. What sort of documentation does the seller have ,  is it likely that he would have the old cardboard logbook ( can't remember if they were still around then) as this would provide far more information than the newer ones?  Could the NOC records provide you with any useful info'?  I would say don't rush into this deal unless either you or the seller can come up with some better historical information. Hope everything turns out ok.