Keith,
Don't be afraid! I rebuilt mine and it was not that hard. There are
not really as many parts as it looks like there is in the diagram. Most
of the parts are springs and washers on the linkages.
The important part of a CV carb is the diaphragm which can rip or
become brittle over time. Be careful when handling the new one. Not
included in the Moss kit, but worth replacing while you have it all
apart are the float (365-505) and the piston spring (365-780). Also not
included is the choke assembly gasket (366-225). I also replaced my
whole air regulator assembly (part#'s 48-51) since it was completely
missing on my carburetor when I bought the car.
The important thing to stress is CLEANLINESS. Thoroughly clean your
workbench before starting and make sure you have room for everything
before it is spread out upon disassembly. You also need to clean
everything thoroughly before reassembly. I used carb cleaner and brake
cleaner. Be careful not to damage the needle or piston while it is
apart. Pistons are machined with the carb body during manufacture and
not available separately. I also took pictures as I went along, both as
a record of the work and in case I couldn't remember how the linkages
went back.
Problematic with the ZS carb is the automatic choke. It wears out
and/or sticks and the carb runs ultra-rich. You won't be able to adjust
the mixture for low emissions and if you air pump and cat are still
functioning the cat will glow cherry red! A fire hazard. There is a
manual choke conversion available, but that only operates the stock
automatic choke assembly. I believe Victoria British stocks the choke
assembly as a replacement part(Moss does not).
Alternative to a rebuild: Whole new ZS carbs are available from The
Proper MG, but are around $500. An alternative is the SU HIF44 carb
Moss and Victoria British sell. Also about $500. I have one on my car
now and it seems to work well. Depends how much you want to spend and
what kind of trouble you are currently having with your stock set-up.
When you put it all back together, there are excellent instructions for
tuning the ZS carb in the Moss catalog. An exhaust gas analyzer (if you
have one) will help also.
Hope some of that helps,
Donny V
1978 MGB
>>> "Keith G." <k2@gernertzone.com> 5/19/2004 11:01:06 PM >>>
Looks like I'm faced with rebuilding my ZS carb, and I'm wondering
how difficult a job it is. The exploded view diagram of the
thousands of parts in the Moss catalog is rather intimidating. I
bought the rebuild kit, but it lacks any instructions whatsoever.
--
Keith Gernert
79 MGB
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