So I have the weber conversion on my S2 petrol and in this hot weather its all over the place.  I have set it up correctly by the book
However:
Fine from cold but as soon as it warms up:
1) Erratic idle - sometimes stalling, sometimes fine
2) Hot start takes ages - prob vapour lock or heat soak
3) Erratic transition from no throttle to part throttle (driveline play exacerbates this)
4) Engine "pops" like mad on the overrun.

So the bottom line is, can this all be fixed or should I be looking at Solex or back to Zenith?
Whats the wisdom out there??
Thanks
Steve 

I'll put my vote in for the Zenith.

I have rebuilt a number of these now, have the original one on my IIA and have a backup waiting in the garage just in case I should need it.

They are a simple carb to honest, not many bits to them and the rebuild kits are about £15. I replaced the throttle spindle, diaphragms and all gaskets in my series one Solex recently and paid about £80!

The Zenith's do suffer from throttle spindle wear but that can be corrected with some machining and some new bushes. I have done a number of these for club members using bronze bushes, the carb exchange do the same I think but they use a plastic, possibly nylon bushes.

What age is you Land Rover as the linkage may need to be changed to use a Zenith. The Zenith linkage needs to be pulled down to open the throttle, the Solex is the other way around.

Craig.

Of course you could go for the best, do away with a carburettor altogether and fit a fuel injection throttle body to it like the Holley Sniper kit.
It has been done and should work great eliminating all the common carburettor issues.

Craig.

Sounds like typical Weber problems to me.

Go for a Zenith. I fixed the spindle wear in mine with a new lower body from https://seriesparts.co.uk/?page=%2F and a gasket kit, plus of course an O ring. Retained the original upper body.

Here are photos of my set up today (1961 but with recon engine)
Looking for a nice simple solution that will fit straight in and fix the problem.
Is there a Britpart carb that would be the simplest solution or am I talking nonsense?

Zenith every time. My 2.5 runs extremely well on my Zenith 36IV which has Solex stamped on the float chamber. It's the original carburettor that was factory fitted.
Webers strangle the engine in the misbelief they deliver better fuel economy but to make any decent progress you have to keep your foot flat on the floor. With mine once I 've got to the speed required I can back off and drive on a light throttle.

Steve, looks like you are getting the same advice I gave you when we met this morning!

When I had my Solex badge Zenith rebuilt by BFS in 2010 or thereabouts I had 3 more rebuilt in the following years just in case. The quality of the original rebuild was so good the other 3 are still back ups.

  Hi

  My Weber works perfectly it starts great (cold), idles nice and will allow the Dormobile to achieve 70 MPH on the flat, I get about 19-20MPG on the highway if I stay under 60MPH. Its been on the rover for over 20 years now.
 
  However Weber's have a few issues.
  Hot starting is one of them. Adding a inline auxiliary electric fuel pump near the petrol tank helps this as well as the other fueling issue. Weber's have a tiny float bowl when accelerating very hard the mechanical pump just can not supply enough fuel the float bowl goes empty and the rover starts bucking, let the gas pedal up for just a second and you can accelerate again as the float bowl fills up again, till it does it again. The added electric pump cures this.

  * Just as a side note the hot starting issue is not all the Weber's fault, the mechanical fuel pump on the side of the block vapor locks especially after sitting for 10 minutes as you run into the store for something. You come out start the rover and it dies in 30 seconds or less, wrapping a cold wet rag around the fuel pump will cool it off enough to get started again.*
  Land rover cured this problem by adding a phenolic block under the mechanical pump much like the block that sits under the weber to isolate it from the heat.

  Victor

 

I have now ordered the Zenith replacement carb to see what happens
I visited Exile this morning for his advice
Before he even looked at the vehicle he said that I had a Weber carb fitted!
I will report back next week

Quote from: Craig T on Sep 08, 2023, 01:06 PMOf course you could go for the best, do away with a carburettor altogether and fit a fuel injection throttle body to it like the Holley Sniper kit.
It has been done and should work great eliminating all the common carburettor issues.

Craig.

Now you're talking. I vote sell the carb.

Quote from: Craig T on Sep 08, 2023, 01:04 PMI'll put my vote in for the Zenith.

I have rebuilt a number of these now, have the original one on my IIA and have a backup waiting in the garage just in case I should need it.

They are a simple carb to honest, not many bits to them and the rebuild kits are about £15. I replaced the throttle spindle, diaphragms and all gaskets in my series one Solex recently and paid about £80!

The Zenith's do suffer from throttle spindle wear but that can be corrected with some machining and some new bushes. I have done a number of these for club members using bronze bushes, the carb exchange do the same I think but they use a plastic, possibly nylon bushes.

What age is you Land Rover as the linkage may need to be changed to use a Zenith. The Zenith linkage needs to be pulled down to open the throttle, the Solex is the other way around.

Craig.

Believe it or not, the Zenith on mine is working via the Solex linkage setup.

A Rover friend over on Instagram sent me the following pic the other day. Pic was taken in the warehouse of a major Rover parts dealer here in the States.  These are all new Zenith carbs from Asia.  They were so bad customers returned them. He said there are more bins of them. The pic was taken before they were tossed into the scrap metal recycling bin.

I had a rubbish Chinese one for a short while. It was only to be a stop gap but that gap was about 10 minutes as no matter where the air bleed screw was the engine ran really rich. I goty money back but not the £20 in carriage charges.
My current carburettor was rebuilt about 13 years ago and once set up has never needed adjustments to the air bleed screw.

I think I would prefer to strip and clean out the weber rather than fit a Chinese 'zenith' of dubious quality.
The weber is easy to dismantle and is actually a very good carb in my opinion. My S2 would pull very well and run at 65 in overdrive on the motorway all day if you wanted. It was faster accelerating than my mates 2a fitted with a (original) Zenith anyway!