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! :neener
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!
Quote from: Alan Drover on Sep 09, 2023, 07:14 AMI 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.
How did you get yours set up? I can get mine set up,but after several drives it starts running rich and doesn't like to idle as good as it should.
Mine is a BFS rebuilt one. I set it up about 13 years ago so not too sure how but as far as I can remember I very carefully screwed the air bleed screw fully clockwise then backed it off about 2 turns. Started the engine and made adjustments until it ran and ticked over smoothly after which I set the timing by ear. No adjustments have been needed since.
It's possible on yours Larry that the castings could be warped or the air bleed screw is moving. Is it held by a spring or locknut?
BFS is Burlen Fuel Systems in Salisbury, England. Unfortunately they no longer remanufacture Zeniths , only supply spares.
BFS is Burlen Fuel Systems in Salisbury
Quote from: Larry S on Sep 09, 2023, 02:18 AMA 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 did suggest to the OP that he should try to find an original Zenith and, if needed, get it rebuilt by a reputable Firm.
Aftermarket carbs used to be awful and not worth fitting. I don't know if there a good new Zeniths around these days?
Quote from: Exile on Sep 09, 2023, 11:19 PMQuote from: Larry S on Sep 09, 2023, 02:18 AMA 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 did suggest to the OP that he should try to find an original Zenith and, if needed, get it rebuilt by a reputable Firm.
Aftermarket carbs used to be awful and not worth fitting. I don't know if there a good new Zeniths around these days?
I have heard of any either. I know of a gent who found an NOS Zenith. He installed it and and said the difference between that one and his old one was like that between night and day.
Quote from: Alan Drover on Sep 09, 2023, 10:55 PMMine is a BFS rebuilt one. I set it up about 13 years ago so not too sure how but as far as I can remember I very carefully screwed the air bleed screw fully clockwise then backed it off about 2 turns. Started the engine and made adjustments until it ran and ticked over smoothly after which I set the timing by ear. No adjustments have been needed since.
It's possible on yours Larry that the castings could be warped or the air bleed screw is moving. Is it held by a spring or locknut?
BFS is Burlen Fuel Systems in Salisbury, England. Unfortunately they no longer remanufacture Zeniths , only supply spares.
BFS is Burlen Fuel Systems in Salisbury
Sounds like the same method we used on mine. We did use a dwell meter and timing light to help.
Each time we get everything set up just right it runs great and then starts going down hill after several drives.
The volume screw has a spring and the throttle screw has a nut.
I still have the original Solex carb on my 1965 MOD. rebuilt about 15 years ago. Daily driver with Steve Parks? electric fuel pump. I tow a 750 kg trailer a lot and have not had any problems with the recent temperature. Some of the plastic insert fuel filters (inside a glass housing) degrade with E10 fuel and block fuel flow.
Cheers, Bill
Exile, the only decent Zeniths available now are rebuilt ones.
Larry, it's possible that the castings are warped if all's ok with the air bleed screw.
As I previously said, NOS Zenith parts available from https://seriesparts.co.uk/?page=%2F you can rebuild yourself.
BFS sell repair kits too.
I'd caution a little bit about assuming that NOS is the Holy Grail. Those kits contain various bits which can deteriorate over time even if just stored. Its the same reason why I tend to grit my teeth when I read about people enthusing about fitting NOS rear main seal kits. Any parts manager worth his salt will recognise that certain things have a shelf life and there is an inherent risk in fitting items which have sat around for long periods. Nobody knows how well they have been stored or how they have been handled. Comeback on the supplier is difficult. At least buying from somebody like BFS, you can be sure that they will sell you the best available quality and hopefully stuff which won't disintegrate at the first sniff of any E numbered petrol.
These are NOS body parts - which I don't believe are available from BFS. With a second hand proper Zenith (but worn spindle), it can be rebuilt quite cheaply.
Rebuilt my 2 Litre carb maybe 4 / 5 yrs back
NOS gaskets are undeniably superior to modern stuff from any supplier !
NOS rubber goods ( carb ) such as seals and diaphragms are to be avoided at all costs !
My rebuilt carb was supplied with supposedly E compliant diaphragms which have since rotted out - did the supplier tell me porkies who knows ?
Edit : the NOS fibre sealing rings are also way better than new, I've found the new stuff can be incorrectly sized ( metric ? ) and also so hard they won't compress to make a seal. Temptation of course is to tighten even more .... Don't do that !!
Anyway be careful what you buy
Quote from: Alan Drover on Sep 10, 2023, 08:15 AMExile, the only decent Zeniths available now are rebuilt ones.
Larry, it's possible that the castings are warped if all's ok with the air bleed screw.
I did the whole heat and sand process incase of warpage.
I can't think of anything else that would cause that problem unless the air bleed screw pointed end is damaged.
O ring quality? Breaking down due to ethanol content? That could create the same effect.
Quote from: Alan Drover on Sep 08, 2023, 02:46 PMZenith 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.
:confused
My 2.5 engine still has a weber as factory fitted- ETC6350 and runs very well, I was told these were standard on the 2.5 engine when fitted to early 110's
I think this is a much better carb than the much cheaper weber as seen on many 2.25 S11 engines
Quote from: Alan Drover on Sep 11, 2023, 11:50 AMI can't think of anything else that would cause that problem unless the air bleed screw pointed end is damaged.
Attached is a pic of the screw. The one on the left is the new one that came with the kit. I opted to reuse the original one because it looked okay to me and the new one had a different configuration.
The second pic shows the new one at the top with one from a donor carb on the bottom.
Perhaps I should try the new one.
Quote from: diffwhine on Sep 11, 2023, 12:19 PMO ring quality? Breaking down due to ethanol content? That could create the same effect.
Hmm... used a brand new O-ring when I rebuilt it back in August 2020. Unless our gas station is sneaking ethanol into the gas I don't use gas with it in it.
But... I don't trust our gas station either. Unfortunately it's the only one around for 20 miles.
Try the new screw very carefully. The original looks though it might have a groove near the point but can't be sure.
Quote from: Alan Drover on Sep 11, 2023, 07:33 PMTry the new screw very carefully. The original looks though it might have a groove near the point but can't be sure.
Out of ignorance... why "very carefully"?
So you don't damage the point when it has gone in as far as it will go.
Quote from: Alan Drover on Sep 11, 2023, 08:44 PMSo you don't damage the point when it has gone in as far as it will go.
Gotcha. I thought maybe something due to design.
In the Zeniths I've rebuilt I haven't yet found a carb body that the new air bleed screw fits into. The new screws all seem to be the wrong thread to me.
I always end up using the original again.
Craig.
Well... we are waiting to see what happens. Found out what the timing issue was... the nut used to clock the dizzy in position was loose. Before messing with the carb we thought we'd check to make sure the timing was better first. Engine fired up immediately and idled very well for over 20 minutes and the RPMs were right at about 525-550.
No that that's taken care of I'm going to wait ans see what happens.
We did look at the screws again though. So.ething just doesn't look right about the new ones. If the carb starts running rich again we will try one of them.
Is there a way to tell if the screw's spring could be worn out?
So here are my further trials and tribulations with the new carb.
I fitted the Britpart zenith carb. Nice easy fit and install as it goes the same was around as the old weber.
Started first time without any adjustment
Played with the idea mixture screw to get a lovely smooth idle
First test run - amazing! landcover pulled like a train - nice smooth transition from no throttle to small opening.
No heat soak or vapour lock like the weber - so very pleased.
After a day or so idle started to falter and revs dropped. Tried to compensate with idle speed screw but idle still really lumpy.
Played with the idle mixture screw but now it seems to do very little - idle is really lumpy and engine seems to be rich. Pulled out the mixture screw and gave it all a blow through - no change
I have closed the garage door for another day as the frustration is getting to me
I can already hear some of you saying "I told you so about Chinese copies!" However, it was running unbelievable smoothly for a day
If you have any sensible suggestions then please let me know
Frustrated of Essex
Steve
Send it back. I had similar problems with a nasty Chinese Zenith and returned it to the supplier. I fitted an old Zenith I had lying around and all was ok again.
I've now had a BFS remanufactured Zenith on the 2.5 in my Series 3 for about 13 years now and once set up it's never needed adjustment.
I'm afraid I've had the same issue as well. Starts off well and then pretty much unusable within a few days. Throw it back at the supplier...
Seems odd that it would go wrong after working properly - and it was perfect
Must be dirt/swarf in the idle circuit
Steve
I think you will find that of you pull it apart, it will have warped. As it cools it sometimes comes back into shape, but they just don't seal properly. You can get the odd good one, but not worth wasting time on in my view. You can tell by the price. £60 for a carb from Paddock. How do you make that and make a profit for that sort of money?
My cheapo Chinese junk one never worked properly at all.
Don't pull it apart, get on to the supplier and insist on your money back as a replacement will likely be just as bad.
See post #12.
If only we could stop buying all that junk but suppliers know that new carburettors are unobtainium. However, I bet there's still a good few original Zeniths out there somewhere just needing a rebuild and that's the obvious way to go although a Zenith in need of a rebuild will cost about the same as new Chinese junk.
I've had Webers, Zeniths, Zenith-copies and now back with a Weber and it runs beautifully in all weathers.
If you're having trouble when it's running hot - how's the engine cooling generally? I ask because I had no end of vapour lock issues on my S3 because a previous owner had fitted an electric fan. Once I got fed up with that thing and sourced an original metal 4-blade fan and a shroud, the constant airflow over the manifolds made a huge difference to the carb temp, even though the water temp didn't change much. I also made a rough heat shield to go above the inlet, but I don't think that helped a lot as it fell off somewhere on a drive and I didn't notice. Neither did wrapping the headers help much - but the airflow did.
Wrapping cast iron headers can cause them to fracture. Stainless steel is ok though.
I've had a thermostatic electric fan on my 2.5 engine Series 3 for years and no problems with vapour lock with the Zenith.
Quote from: Alan Drover on Sep 15, 2023, 02:23 PMIf only we could stop buying all that junk but suppliers know that new carburettors are unobtainium. However, I bet there's still a good few original Zeniths out there somewhere just needing a rebuild and that's the obvious way to go although a Zenith in need of a rebuild will cost about the same as new Chinese junk.
What really bothers me is that the parts dealers KNOW the Chinese clones are garbage,yet they still offer them.
As to NOS... I know a guy who found one, and replace parts like the O-ring. He said the difference between that one and his old one was like that between night and day. He never said how much he paid for it, but he found it on eBay.
Quote from: Alan Drover on Sep 15, 2023, 08:32 PMWrapping cast iron headers can cause them to fracture. Stainless steel is ok though.
I didn't know that, guess I was lucky. Although in truth, you can't actually wrap Land Rover headers that effectively as the inlet is so tight.
Quote from: stevesharpe on Sep 14, 2023, 05:41 PMSo here are my further trials and tribulations with the new carb.
I fitted the Britpart zenith carb. Nice easy fit and install as it goes the same was around as the old weber.
Started first time without any adjustment
Played with the idea mixture screw to get a lovely smooth idle
First test run - amazing! landcover pulled like a train - nice smooth transition from no throttle to small opening.
No heat soak or vapour lock like the weber - so very pleased.
After a day or so idle started to falter and revs dropped. Tried to compensate with idle speed screw but idle still really lumpy.
Played with the idle mixture screw but now it seems to do very little - idle is really lumpy and engine seems to be rich. Pulled out the mixture screw and gave it all a blow through - no change
I have closed the garage door for another day as the frustration is getting to me
I can already hear some of you saying "I told you so about Chinese copies!" However, it was running unbelievable smoothly for a day
If you have any sensible suggestions then please let me know
Frustrated of Essex
Steve
Steve, when we met didn't I suggest getting an old original Zenith, and getting it refurbished by an experienced Company?
If I didn't, I should have.
Like many on here, I have been through the same thing as you have with an aftermarket Zenith, many years ago.
The only thing they are good for is throwing at pigeons, to get them off your vegetable patch.
It is why I keep a few original Zeniths for the sole purpose of having them refurbished if I need them.
I am rapidly coming to that conclusion!
I plan to bung the weber back on until I can find the Zenith solution
Many thanks
Steve
I keep 3 refurbished Zeniths and 1 in need of refurbishment just in case.
I have a donor Zenith I'd like to rebuild, but I had to get the donor to replace a spring that broke in order to rebuild the one on Grover.
In the pic you can see an arrow pointing to the part of the spring that broke. Anyone know where to get replacements?
The only place I know is BFS in the UK but I suspect carriage will be horrendous. I've found it in the spares catalogue but it doesn't have a part number and is not included in the rebuild kit. Is there a spring supplier in the States that could help?
Are there any on the cheap Chinese copies that are usable?
If not, somebody must have one and it's so small it wouldn't be a problem to bung one in the post.
Larry
I've just been through the same process with my Zenith. After several attempts at putting a 'service kit' in it I went through the same cycle of having it run perfectly for a couple of days then going rich again with the bleed screw ineffectual.
Problem turned out to be a warped case and top, ended up spending best part of a day lapping them with wet&dry on a piece of glass, along with the wrong spec o ring in the aftermarket 'service kit'. Got onto a local seal supplier who supplied some viton o rings and it's been a sweet runner ever since. The kit o rings were the wrong compound and were going rock hard after a couple of days leading to leaks even after the case and top had been lapped flat. this may be the issue with the reproduction Zeniths as well.
With the o ring size I was kind of flying a bit blind, and assuming the size in the aftermarket kit was correct. They were 1 3/16 x 3/32, which was a standard size. Does anyone know if this is correct? I suspect that while this size seems to work, it may be a little small, although the next biggest imperial o ring would be too big.
Was it a genuine BFS service kit?
I've had a look in my carburettor box but nothing. BFS returned all the replaced parts when they rebuilt my carburettors but no sign of them. I suspect they were ditched. I don't have a junk Chinese one only genuine rebuilt ones.
I thought of posting one if I had a spare but as it's metal I wonder if there are metal detectors at customs posts which it would trigger prompting a terrorist alert?
Quote from: Alan Drover on Sep 17, 2023, 11:14 AMWas it a genuine BFS service kit?
I've had a look in my carburettor box but nothing. BFS returned all the replaced parts when they rebuilt my carburettors but no sign of them. I suspect they were ditched. I don't have a junk Chinese one only genuine rebuilt ones.
I thought of posting one if I had a spare but as it's metal I wonder if there are metal detectors at customs posts which it would trigger prompting a terrorist alert?
I've posted plenty of small metallic items to the US. Not a problem - just state contents as "a spring" and state "of no commercial value" nothing more. Do not say that its a used automotive part - US Customs don't like that.
Quote from: Graeme on Sep 17, 2023, 10:44 AMLarry
I've just been through the same process with my Zenith. After several attempts at putting a 'service kit' in it I went through the same cycle of having it run perfectly for a couple of days then going rich again with the bleed screw ineffectual.
Problem turned out to be a warped case and top, ended up spending best part of a day lapping them with wet&dry on a piece of glass, along with the wrong spec o ring in the aftermarket 'service kit'. Got onto a local seal supplier who supplied some viton o rings and it's been a sweet runner ever since. The kit o rings were the wrong compound and were going rock hard after a couple of days leading to leaks even after the case and top had been lapped flat. this may be the issue with the reproduction Zeniths as well.
With the o ring size I was kind of flying a bit blind, and assuming the size in the aftermarket kit was correct. They were 1 3/16 x 3/32, which was a standard size. Does anyone know if this is correct? I suspect that while this size seems to work, it may be a little small, although the next biggest imperial o ring would be too big.
Very interesting, I am wondering why a warped carb body would cause it to be too rich and the idle mixture ineffectual
I would have though any air leak would make it too lean
If I could fix my chinese Zenith then I would be happy to have a go
I did read why a warped casting causes a rich mixture. I believe it's something to do with fuel overflowing the float chamber into the inlet but not 100% sure. Admittedly it sounds odd.
I know we are all knocking the Chinese made Zenith, but there must be a fix. Mine is clearly flooding with fuel and bypassing any effect from the idle mixture screw. Most likely cause would be the float/float needle not cutting off the fuel supply.
I am tempted to start looking closer - might be quite simple as it has run perfectly. For example, if float has sunk it would always flood
Any other expert ideas or thoughts?
Steve
As it's new don't mess about with it. Contact the supplier. If you dismantle it the guarantee is void. Look for a genuine Zenith to refurbish.
With the reproduction Zeniths, I'd try a better o ring in one and see what happens.
The rebuild kits and repro carbs seem to come from the same source, and after my experiences I'd be looking at the o ring in the repro carb, after checking the casting faces are flat.
Heya everyone...
In re the Zenith currently on Grover, before rebuilding it I did cook it and, very gently wet sanded it on a pane of glass. See the pieces bellow.
The father-in-law helped with the timing a few weeks ago and the whole thing got worse - sputtering, not wanting to fire, and some light backfiring. Last Tuesday we tackled it again and what figured out what was causing all of that - he didn't get the bolt that clamps the dizzy tightened enough.
Once that was dealt with I fired up Grover - started up on the first attempt and was idling well at 500rpms. We let it idle for about 20 minutes, no problems. Once it was warm it was idling at 550rpms.
Took Grover for a spin and he handled really well. Took him for another spin Saturday and all went well.
So... I'm going to wait and see how long it takes for the carb to start running rich again.
Now... if it does start running rich again we will try one of the new screws. This leads to another question - how can you tell if the adjustment screw spring is worn out? I have several version of the spring, some have 5 coils and some 6 or 7. Pic attached below as well.
Quote from: Alan Drover on Sep 17, 2023, 08:24 AMThe only place I know is BFS in the UK but I suspect carriage will be horrendous. I've found it in the spares catalogue but it doesn't have a part number and is not included in the rebuild kit. Is there a spring supplier in the States that could help?
Not sure if I know of a spring supplier here that could help. Diffwhine has given me an idea though... perhaps the chap that sent me the pic of the Chinese clones could tell me if they have those springs.
I see the spring listed in the exploded view within the following, but no part number. Is there a link, or pic,to the parts list you have?
https://zenithcarb.co.uk/zenseriesiv#:
Quote from: Graeme on Sep 17, 2023, 10:44 AMLarry
I've just been through the same process with my Zenith. After several attempts at putting a 'service kit' in it I went through the same cycle of having it run perfectly for a couple of days then going rich again with the bleed screw ineffectual.
Problem turned out to be a warped case and top, ended up spending best part of a day lapping them with wet&dry on a piece of glass, along with the wrong spec o ring in the aftermarket 'service kit'. Got onto a local seal supplier who supplied some viton o rings and it's been a sweet runner ever since. The kit o rings were the wrong compound and were going rock hard after a couple of days leading to leaks even after the case and top had been lapped flat. this may be the issue with the reproduction Zeniths as well.
With the o ring size I was kind of flying a bit blind, and assuming the size in the aftermarket kit was correct. They were 1 3/16 x 3/32, which was a standard size. Does anyone know if this is correct? I suspect that while this size seems to work, it may be a little small, although the next biggest imperial o ring would be too big.
I just posted a reply showing the parts I heated and sanded.
As to the O-ring - the one that came with my rebuild kit seemed to fit perfectly, but having never rebuilt a carb I'm clueless as to how it should fit. No clue what it is made of though.
In addition to all the above information in re the Zenith on Grover...
I had never rebuilt a carb before in my life, I always went through someone else. I decided to do this one myself, figured if I could rebuild all the other stuff I rebuilt, why not the carb.
So, I got all the info I could, talked to several Rover owners, watched videos and took my time.
Once it was completed I reinstalled it and tested it out - fired right up. But, something did happen that I wasn't expecting. The bottom part of the carb got icy cold and I noticed a small puddle of moisture at the base, the red arrow in the pic is pointing to it. This kind of freaked me out and the first thing that came to mind was leaking gas.
I shut the engine down and started contacting a couple mechanics who I had spoken to about it beforehand. They told me that all was good and the cold and condensation was a sign it was in good working order.
Larry, my parts list is a book supplied by BFS which covers Solex, Zenith, Stromberg and Pierburg carburettors. It has exploded diagrams of the carburettors and shows the parts that come in various kits. The spring you want is not in any kit.
I reckon a spring from a Chinese reject would do fine. While you're there I'd grab a handful.
I don't know if this is of any help. Maybe it could be downloaded to the technical section by one of our computer whizz kids.
Sorry, sideways again.
..and here's the Solex if of any use.
Sideways again.
Quote from: Alan Drover on Sep 18, 2023, 07:57 AMLarry, my parts list is a book supplied by BFS which covers Solex, Zenith, Stromberg and Pierburg carburettors. It has exploded diagrams of the carburettors and shows the parts that come in various kits. The spring you want is not in any kit.
I reckon a spring from a Chinese reject would do fine. While you're there I'd grab a handful.
Thanks Alan. I have contacted my source about the springs, but have as yet heard back. I'll keep all y'all informed though.
To continue the story. I have now pulled off the Chinese Zenith and put back my old Webber. The Webber definitely has less power - probably due to the smaller bore.
I am now on the hunt for an original Zenith to rebuild.
Should I be be buying an overhaul kit or a rebuild kit? Not really clear what the difference is
Thanks
Steve
Get a rebuild kit. If you can make out the photo I posted at #70, it shows what's in both kits.
My contact was able to rescue a handful of those funky springs from the recycling bin and we'll be sending them my way.
That will save a lot of bother trying to import them and you'll have plenty of spare ones.
If it is the spring on the air bleed screw you are referring to, not all of them had a spring.
One of my earlier Zeniths has a brass lock nut on the thread which looks original. Bit fiddly to operate but once locked down, you won't be adjusting it again in a hurry.
Craig.
One of the Zeniths BFS rebuilt forr had locknuts on both throttle and air bleed screws. I had them replaced with springs.
Quote from: Craig T on Sep 22, 2023, 09:09 AMIf it is the spring on the air bleed screw you are referring to, not all of them had a spring.
One of my earlier Zeniths has a brass lock nut on the thread which looks original. Bit fiddly to operate but once locked down, you won't be adjusting it again in a hurry.
Craig.
Nope, the spring pictured in post #54.
So I finally given up on the chinese Zenith and the weber.
Bought an old original Zenith and a rebuild kit
However, just looked at my carb and spotted what looks like a crack in the spacer (see photos). Could this be the source of all my problems - although I doubt it as engine runs rich rather than lean.
If I fit a new spacer should I use gaskets or not?
Many thanks
Steve
Yes - ideally a gasket either side. The air leak from the crack may be adding to your problems. Strange things happen when air flow is disrupted.
There has been a lot of talk about Webber's and Zenith, be they original or Chinese copies, but nothing about Solex ???
Mine has the original Solex fitted and runs just fine. Aren't they an option?
I love a solex, externally mounted jets so changing/cleaning them is a doddle, metal float and no o-rings for E10 to destroy. Possibly a little more thirsty than a zenith, but not enough to worry about😇
Jon
I like my Weber carb and my Webber bbq😂. The Weber carb has given almost 10 years of faultless service and returns 22-24 mpg on a long run. My Webber bbq has given 20 years of faultless service too :essen
Quote from: nathanglasgow on Sep 23, 2023, 05:32 PMI like my Weber carb and my Webber bbq😂. The Weber carb has given almost 10 years of faultless service and returns 22-24 mpg on a long run. My Webber bbq has given 20 years of faultless service too :essen
Which Webber are you using?
Just a quick update on my carb saga.
Firstly, I have now bought an original second hand Zenith and am having it refurbed by Carburettor Exchange in Leighton Buzzard (although there is a back log of 8 weeks).
In the mean time, I dismantled my Chinese Zenith copy. I found that the large rubber ring that seals around the venturi between the upper and lower chambers was quite different from the one in a rebuild kit I had. The rebuild ring was a much tighter fit on the venturi - so I fitted it! Lo and behold, the carb stopped over fuelling and idled nicely. It seem that this rubber ring may well be the main issue. Hope that helps anyone struggling to get these copy carbs running
I've found that dropping the O ring into hot water before fitting helps assembly as does a smear of silicone grease.
This helps the top cover go on easily and you don't have to use the cover screws to pull it together. Seal was supposed to be NOS, either way warm and slippy is good.
Original Solex - a good carb giving a punchy drive and reliable too.
I know have a very limited amount of the springs pictured below. I'm not sure if I'll be able to get any more or not.
If anyone needs one let me know.
:cheers
Larry
Quote from: stevesharpe on Sep 28, 2023, 10:47 AMJust a quick update on my carb saga.
Firstly, I have now bought an original second hand Zenith and am having it refurbed by Carburettor Exchange in Leighton Buzzard (although there is a back log of 8 weeks).
In the mean time, I dismantled my Chinese Zenith copy. I found that the large rubber ring that seals around the venturi between the upper and lower chambers was quite different from the one in a rebuild kit I had. The rebuild ring was a much tighter fit on the venturi - so I fitted it! Lo and behold, the carb stopped over fuelling and idled nicely. It seem that this rubber ring may well be the main issue. Hope that helps anyone struggling to get these copy carbs running
For grins-n-giggles... here's a pic showing the O-ring that came off of mine as opposed to the one in the rebuild kit. The Zenith was first rebuilt (not by me) sometime around 2006 or so; assuming the O-ring was replaced with the appropriate type it makes me wonder how fast those things deteriorate.
With the amount of ethanol on fuel these days, clearly not long!