Virtually none compared to a Zenith in good condition - but if your
Zenith is warped or otherwise unrepairable it would make a good replacement.

I fitted a webber to my 2a and it iced up regularly stopping the engine
after about 20 miles of driving. I made a few enquiries I was told "it
wasn't unheard of". Mine was fitted with a Solex, the casing had worn
at the spindles letting in air making starting difficult.
With the benifit of hindsight I would repair or replace the old carb
with one of the same make or put up with the poor starting.
If the existing carb is in reasonable conition I would leave it alone.

HTH

Paul

I've heard that the Webber is not good at supplying fuel at extreme angles,
which is why the Zenith and Solex were chosen.

Could be wrong though, not fitted one myself.

Paul

put one on the series II, to replace a very dodgy old solex.  worked fine,
IIRC.

nor did I notice icing as a problem - mine was run through the standard
filter and inlet though.

carb icing may happen more with unleaded.  but then again, it's solveable by
putting the intake near the exhaust manifold, so it draws warm dry air into
it in winter.

I fitted a new Webber to my Srs11a about a year age and have had no problems
with it what so ever after the initial setting up,I fitted it as the
"original" was beyond ajustment without an overhaul and more importantly it
was free.

There's serious issues sadly with all three carbs... Zenith's I'd have to
say from my experience are by far the worst of the lot. There are serious
manufacturing problems - the bodies were never correctly heat treated, so
nearly all are warped to some extent, and run rich (or very rich)! I have a
collection of around 8 crap old ones. A friend in the trade recently bought
5 brand new - all were warped from manufacture and totally useless. They
also suffer from wear around the shafts on the throttle venturi. This leads
to petrol running down the outside of the carb onto the manifold. I've tried
all the tricks including thick gaskets and plugging holes to get round the
warping, but once they're gone they're gone!!

Solex were dumped by LR in favour of the zenith. As far as I know they're
not great. Tend to give a lower power output, and not as good economy as
Zeniths. The only ones I've come accross have been old and knackered. I
don't think they're particulaly available either.

The Webers are OK, but have the following problems:
The diaphragm on the enrichment pump dies after a while, leading to weak
running/poor acceleration and more frequent icing. The part also isn't
available from anywhere leading to total carb replacement. I've got one
knackered one in the shed.. They also are quite bad on slopes. Mine often
gave me trouble on fairly minor side slopes - very rich running and
necessitating a foot constantly on the throttle to keep the engine running.
Icing up has been a problem too normally after a mile or two in cold
weather. Best way to avoid is by light throttle openings only  until the
engine's really hot. Having a radiator muff helped that too. On the plus
side I got an extra couple of mpgs on a weber. They do need to be used with
an inline filter - lots more prone to blocking up than the other 2.

By far the best option is to fit an SU or Stromberg. You'll need to get
someone to make a 90 deg adapter bend for the inlet, but from experience on
many cars they're superb carbs when set up and don't go wrong often. Never
tried this conversion on an LR yet, but saw it done on a IIA - owner
reported superb results & 23mpg!! If not the weber is the best of the
others.

Have fun...

Andy

If you've got a solex, you'll need to change the throttle linkage by
the carb, as it has to move in the opposite direction. I think the
Zenith is a straight swap, barring the adapter plate.

I've never liked the Solex carb myself, but that's down to personal
choice. The Zeniths tend to suffer from poor quality
materials/manufacture.

The two downsides to the weber are the small float chamber, which
gives problems on sideslopes, and minimal reserve should your fuel
pump give trouble.

Secondly the cold start seems quirky, requiring full choke for
starting, but very quickly requiring only a minimal amount of choke
for idling, otherwise it stops. Then you get it idling on a little
choke, only to find it coughs and dies, or hesitates when you attempt
to accelerate. Pulling the choke out some more cures this problem, but
results in far too rich idling, which will cause it to conk out. Once
warmed up, it's fine though.

As for performance/economy the Weber and the Zenith seem largely
indistinguishable, both seem to give roughly the same power. If your
carb is in good order, then keep it, I don't see any point in changing
it for the sake of changing, it won't benifit you an awfull lot.

Fitting an SU carb makes a marked difference, but you have to factor
in the cost of both the carb and a manifold as well, which makes it
expensive.

Alex