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(Sigh.)A common mistake made by people who think they are cleverer than they are is to suggest that because they have never seen something it doesn't exist.AFAIK all Mk III's in all markets used 'Shrouded' carbs. Hence my request for a shot down the venturi.MkI/II/III Le Mans engines are all essentially the same in terms of bore/stroke/combustion chamber shape and valve size.A common Tuning Modification' made by the ignorant is to fit Mk I/II jetting to MkIII carbs because everybody knows that the only reason the Mk III uses much leaner jetting is because of some tinfoil hat conspiracy by the 'Government' and probably the Illuminatti and anybody else you want to have a conspiracy about who wanted to restrict your fun and curb 'Pollution' which we all know is a lefty plot.In fact the changes were made to take advantage of the greater cooling of the squarefin head design to promote better fuel economy.*IF* these carbs are the earlier, unshrouded, type? Then Mk I/II jetting is a fine starting point. If however they are the original carbs as fitted to a Mk III fitting MkI/II jetting will turn it into a thirsty, gutless pig. This is a pity as it will also cause premature wear in the engine but if that is what floats your particular boat? Be my guest.Pete
slepsnysThe pics you posted clearly shows that your carbs are not shrouded, even if they have the B stamp on them, so they are to be jetted as the LM850 and LMII PHF D type. Somebody obviously changed the atomizers.The casting is of course the same for the PHF D and the PHF B versions, and they both additionally have the D or the S suffix stamped on them. D for "destra" and S for "sinistra",- right and left.So,- : PHF 36 BD and BS,- and PHF 36DD and DS.
Not in my memory or by Guzzi factory and Dell Orto booksAll of them were B type, just later ones have shroud and jets but not marked differentlyone visible difference on first LM to 3's is brass spigots for vent hoses, not in OP's picturesBut OP's carbs origins may never be known,
As I`m sure most of you already have figured out, I don`t come here in any "expert capacity",- and I`m happy to be corrected and learn something new in addition to all the other useful and interesting things I`ve learned here.