Good Day all ye Joyful & Triumphant types
>Jeff Wagner wrote:
>>> I've never found any way to adjust the
>>>mixture on these carbs, other than to find and fix all the air leaks.
>
Tom Gentry wrote:
>
>I have owned a '68 TR-250, and two '72 TR-6s as well as working on various
>other Triumphs and have always been able to adjust the carb mixture with the
>ZS tool even though the manuals often referred to the carbs as
>"non-adjustable" or "tamper proof". Is there another type of ZS carb I am
>unfamiliar with?
According to Haynes ZS manual, for the series CDSE and CD-2SE
carbs, there are 3 alternative arrangements of jet & needle assemblies:
1)<Fixed jet and fixed (pre-set) needle.>
The jet is pressed in the carb body and non adjustable or removable.
The needle is pre-set in the air valve guide and locked by a conventional
locking screw. The position should not be altered (according to Haynes).
2)<Fixed jet and adjustable needle>
The jet is as above. The needle assembly height is adjustable through
a limited range by an adjusting screw fitted in a special air valve
guide rod. A keyway and peg arrangement replaces the locking screw
and permits vertical movement while preventing rotation, maintaining
the angular relationship with the jet.
3)<Adjustable jet and fixed (pre-set) needle>
The needle assembly is as #1 (conventional locking screw)
The jet orifice slides in a bore in the carb bridge and is spring loaded
downwards. It is retained by a bush & threaded sleeve arrangement.
The bottom of the bush projects through the float chamber cover where
it is sealed by an O-ring, and is castellated to accept a special
adjusting tool. A shielding cap is clipped over the bottom of the bush.
I don't think there is any way to tell these types apart without some
disassembly of the carb. It would be prudent to find out which type
carb you have before exerting too much force with "the tool".
I believe all of the above mentioned carb flavours would be called
"emissions carbs" & "tamper proof" and adjustment would be
discouraged by most manuals.
Hope this helps,
Bob Sykes
75, 78, 78 Spitfires
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