Old Leafsprung Land Rovers

Ive never really been able to set up the zenith carb pwrfecly,however now it refuses to idle or run at all on petrol (and my LPG tank is empty  )

It seems the mizture is all wrong,the mixture screw can be screwed in or out almost completly with no effect.

Im sure ive read in yhe past these carbs commonly warp,resulting in the above symptoms.  Any opinions greatfully received...

Also anyone know of a good carb specialist in birmingham area,as I guess replacments are not worth the money?  Cheers

Already tried advancing/retarding timing (as I replaced the dizzy so thought it might be out) but no change, that's why I think its the mixture ( like I say its never been 100%, but as I run on LPG 99% of time i foolishly ignored the problem what a  :****: i am..)

So i guess its just been getting worse and i never noticed due to relying on LPG.
I've a spare Webber ICH i may pop on see if that makes any difference

Cheers Dave

Cheers Doug,

well I' ll pop the Weber back on tomorrow hopefully this gives me a quick fix. I'll have a little search for rebuild kits now.
Is it a simple enough job to rebuild these then? I was thinking it may be a specialist job?

This is why it pays to thoroughly check out second hand Zeniths, because "It worked well when it was removed" may have been true many months ago when it WAS removed, but in the intervening time the O-ring has dried out and the first time you use it the float chamber contents cascade into the manifold, the idle mixture screw has no effect and you think "the scoundrel gave me a duff part" (or words to that effect).

It really is quite a straightforward bit of kit; I just made reference to the exploded diagram that you find in the manual, and went through the rebuild kit before taking the carb apart (so I could identify where everything went).  They are quite simple things really, and there isn't a great deal you can do aside from replacing gaskets, O-rings, checking the float height is set right (important that because it can also cause running issues if it isn't) etc.  Not difficult, and from memory last time I did it took about an hour.

I don't know what to make of the warpage issue.  As I understand it the idea is that the top warps in relation to the bottom due to the carb getting hot, thus moving the emulsion block inside and disturbing the O-ring seal between the emulsion block and the base of the float chamber (you will see when you take it apart) thus causing leaks there.  Surely though a) it can only warp a little bit, and this would be taken up by the O-ring (unless it is already brittle) and b) there's a plastic insulation block between manifold and carb which presumably stops the carb getting too hot anyway.

So rebuilding is an OK job, but what of spare parts. I see Craddock's sell a all-makes rebuild kit, any good? Or any good suppliers of genuine kits?

Last two I did I used one genuine parts kit, and one blue box kit.  The genuine kit only came with the gaskets, seals and accelerator pump diaphragm, the blue box kit came with spindles and replacement butterflies as well.

The "moving parts" in the blue box kit weren't great - but then I wasn't going to use them anyway - but the seals and gaskets were more than up to the job.  The genuine stuff was good as you would expect.

Yeah apparently they bad for warping but I did think the same thing, apparently flatting all surfaces on a piece of glass with wet and dry can fix it. I guess specialist have special kit to check for this, but if/when I rebuild mine i'll flat it on glass cant hurt I guess 

Cheers 

Indeed it can't hurt, but I wonder how many people do this, put it back together and say "it must have been the warping that did it because now it is fine"...  Whereas it was probably all the new gaskets etc that they put in that actually made the difference.

After all, you would replace all the old seals and gaskets anyway if you were going to take your carb apart to flat the mating surfaces, wouldn't you?

Doug has it spot on in my opinion, the Zenith in my experience does have a tendency to throw a hissy fit when not run on petrol for some time. Oddly the new genuine Zenith fitted on the 109 has been spot on for years run on gas, the refurbed carb from Carburettor Exchange lasted less than a year. I've now gone SU on the 88 so haven't bothered with the other Zenith, my betting is the O ring has given up.