The Solex B40 PA4IO-5a Carburetor thread! [Archive]

incisor

11th September 2012, 11:32 AM

I have two types of Solex B40 PA410-5a

https://www.aulro.com/afvb/images/imported/2012/09/1014.jpg (http://www.flickr.com/photos/niknodave/7974961023/)
DSC_8952 (http://www.flickr.com/photos/niknodave/7974961023/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

one with a venturi tube

https://www.aulro.com/afvb/images/imported/2012/09/1015.jpg (http://www.flickr.com/photos/niknodave/7974933154/)
DSC_8958 (http://www.flickr.com/photos/niknodave/7974933154/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/1016.jpg (http://www.flickr.com/photos/niknodave/7974939448/)
DSC_8955 (http://www.flickr.com/photos/niknodave/7974939448/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

note the brass blank

and one without

https://www.aulro.com/afvb/images/imported/2012/09/1017.jpg (http://www.flickr.com/photos/niknodave/7974934849/)
DSC_8957 (http://www.flickr.com/photos/niknodave/7974934849/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/1018.jpg (http://www.flickr.com/photos/niknodave/7974936971/)
DSC_8956 (http://www.flickr.com/photos/niknodave/7974936971/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

note the brass jet

incisor

13th September 2012, 12:00 PM

https://www.aulro.com/afvb/images/imported/2012/09/933.jpg (http://www.flickr.com/photos/niknodave/7981436656/)
solex_mt_page1 (http://www.flickr.com/photos/niknodave/7981436656/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/934.jpg (http://www.flickr.com/photos/niknodave/7981434685/)
solex_mt_page2 (http://www.flickr.com/photos/niknodave/7981434685/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

incisor

20th September 2012, 02:06 PM

what a brand new one looks like

https://www.aulro.com/afvb/images/imported/2012/09/586.jpg (http://www.flickr.com/photos/niknodave/8005198380/)
newsolex1 (http://www.flickr.com/photos/niknodave/8005198380/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/587.jpg (http://www.flickr.com/photos/niknodave/8005197932/)
newsolex2 (http://www.flickr.com/photos/niknodave/8005197932/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/588.jpg (http://www.flickr.com/photos/niknodave/8005197304/)
newsolex3 (http://www.flickr.com/photos/niknodave/8005197304/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/589.jpg (http://www.flickr.com/photos/niknodave/8005196616/)
newsolex4 (http://www.flickr.com/photos/niknodave/8005196616/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

https://www.aulro.com/afvb/images/imported/2012/09/590.jpg (http://www.flickr.com/photos/niknodave/8005196126/)
newsolex5 (http://www.flickr.com/photos/niknodave/8005196126/) by NiknoDave (http://www.flickr.com/people/niknodave/), on Flickr

courtesy of land lover treasure shop (http://stores.ebay.com.au/Land-Rover-Treasure-Shop)

whom i purchased a second hand unit from. when it arrived here it was missing a jet or two and there were some other flaws i was less then impressed with.

they replaced it with this.

excellent service indeed! and i thank them kindly.

EISTO

8th June 2016, 04:11 AM

Hi!
I'm refurbishing a Solex 40PA10-5 carb for a 1964 Series II and noticed a strange copper tube near the inlet manifold flange. The previous owner has cut the tube and attempted to plug the stump with a piece of heat shrink tubing and a nail :(. See attached picture.

Anyway, I can't find a single picture or reference that explains the purpose of this tube. Since I don't have access to the car myself, it's difficult to see what was connected at the other end.
Any input would be appreciated.

Br,
Einar

Pedro_The_Swift

8th June 2016, 06:33 AM

wow,, thats had a hard life!

Busted Syncro

8th June 2016, 06:33 AM

G'day Einar,

The tube in the photo is part of the vacuum advance circuit.

This tube goes to the vacuum advance diaphragm on the ignition distributor.
It is important and necessary for the operation of the ignition system.

The port in the Solex is a metric thread M6 x 1.00 and you use an olive on the tubing to seal the connection. The tubing is 0.125" (inch) diameter.
The part number for the tube nut is 260707. They are made of steel and break often and probably you will have to make one out of hex stainless steel.

Good luck
Chris

EISTO

8th June 2016, 09:47 PM

That's very valuable input, Chris, and thanks or welcoming me.

The tubing is indeed 1/8", but as far as I can see the port has the same diameter (not 6mm) and there is no apparent way of removing the tube.
There is however an open threaded port right next to it (see picture) which looks like it could be 6mm (haven't measured it yet). It's also difficult to see if those two ports communicate, i.e. if there is an open passage between them.

If there is, does this mean I can cut/blind the old tube and mount a new one in the threaded port using the part number you refer to?

I don't know how much vacuum we are talking about, but is it possible to use a thick-walled flexible hose -such as a fuel hose- instead of messing about with stiff copper tubes, or will the hose collapse?

Einar

P.S. Pedro: It has indeed had a hard life. Some metric violence has also been exerted. Someone removed the 5/16" nuts and used raw force to mout 8mm nuts instead. It hurts to look at it...

B.S.F.

8th June 2016, 10:16 PM

EISTO

8th June 2016, 11:37 PM

Busted Syncro

9th June 2016, 07:02 AM

G'day Einar,

Yes the port you refer to is as others have reported is for the volume control screw (idle mixture adjustment.)

Yes the tube nut has broken off and the wall thickness is only 1mm so it is hard to see. A tricky job to remove it with the pipe in and only takes time or usually a hard pull will get the tube out. Usually the broken bit can be unscrewed out.
Use plenty of penetrating oil first by blanking off the hole into the carby throat and filling the broken tube up and leave for awhile to soak. Use a fine tipped screwdriver blade inserted in the centre of the broken tube and try and back out the screw. Maybe fine pointed "broken screw extractor" could be used?. It will come out.!!!!

Yes you could rethread to a larger size however think you will get the broken bit out and find the olive at the bottom of the hole.

Yes the original tube is all steel because of the vacuum however the Zenith carby uses a short length of rubber hose to connect to it. The Solex uses the tube nut and olive method to connect to the carby.

Hope this helps
Chris

EISTO

9th June 2016, 10:12 PM

Thanks Chris, I appreciate it. I'll try using some WD40 and do as you say, hopefully it will come out. I couldn't find any online store selling the tube assembly (279724), so I'll try to get hold of whatever parts are available -such as the oilve and screw- and pehaps buy some 1/8" tubing and assemble it myself.

Einar

Busted Syncro

10th June 2016, 08:35 AM

G'day Einar,

Just a further thought: The problem of re tapping the vacuum port to a larger size may cause another problem. It may break into the volume control screw port and cause air to leak into the idle circuit.

If you cannot repair the original vacuum port I use the 13mm boss in the casting below the vacuum port for a vacuum gauge port.

Chris

schuy1

13th June 2016, 06:32 PM

As an alternative to retapping the hole larger I have had good success with this Loctite Form A Thread Repair KIT Gray 4 8ml | eBay (http://www.ebay.com.au/itm/Loctite-Form-A-Thread-Repair-Kit-Gray-4-8Ml-/131772684192?hash=item1eae4397a0:g:CH4AAOSwiylXA9R t)

The best thing is you can form what ever thread type you wish :) The original fittings are being made in unobtaniam now I think.

EISTO

14th June 2016, 02:10 AM

___

EISTO

14th June 2016, 02:13 AM

Hi,

Chris: Could you explain (perhaps show a picture of) what you mean by "the 13mm boss in the casting below the vacuum port" and how this works?
Scott: Good stuff. I don't think it'll work in this case (see text below) but I'll definitely keep it in mind for future ruined threads.

My cousin (the owner) and I tinkered with the Solex last weekend, but didn't get much further. Strangely, there is absolutely no trace of the broken "screwed union". Only the olive remains.
When I scratched the walls of the hole with a screwdriver, I noticed it was aluminium; not steel. Was the screwed union made of aluminium, and is that what I'm seeing? I could swear what I'm seeing is part of the carburetor body; there is no trace of the screwed union, although the hole is just 4mm across.

Anyway, there is no way to restore the original thread, so we're planning to drill and tap the hole. I though I'd try making a 6mm or 1/4" thread. Hopefully, this will not cause me to break into a nearby channel.
The plan is to insert a barbed hose fitting for hoses with 1/8" inner diameter and use a small length of hose to connect the copper pipe to the carburetor. Same thing on the distributor side.

Therefore: What is the thread size of the connection nipple on the vacuum unit?We're talking Series IIA, not Series II (my mistake). I need to know in order to buy the correct hose fitting. The car is located 2500 km away in northern Norway, so I can't measure it myself...

I really appreciate your help :)

Br,
Einar

Busted Syncro

14th June 2016, 07:26 AM

G'day Einar,

The 13mm Boss I refer to is in your photo you posted and is 20mm below the centre of the vacuum port. It is the raised round casting and you can drill and tap the required size hole in this and a small 1.5mm hole through the throat wall for the vacuum.

However, if you are going to retap the original vacuum port obtain the fitting first to determine the thread type. It can be BSP, NPT or other and note you are aware of breaking into the volume control screw port.

The thread on the distributor vacuum connection end could be a number of thread types or a tube for rubber hose connection. Unfortunately you are going to have to measure it. It may not be an original distributor as well.
(I don't know what the original thread is. All mine are tube and rubber hose connections.)

Foot Note: The 1.5mm hole thru the throat wall is not in the centre of the M6 hole. It is on the lower edge. This allows the throttle plate to clear the hole and not block it when the engine is idling.

Hope this helps.
Chris

B.S.F.

14th June 2016, 12:04 PM

The thread for the vacuum pipe appears to be M6, which makes sense considering SOLEX is or started off as a french company. I think all the bolts on the carby are metric.
.M.

JDNSW

14th June 2016, 07:56 PM

Both Solex and Zenith are originally French, and all threads are metric - but I would not bet on them all being ISO metric!

John

EISTO

15th June 2016, 08:45 PM

Chris; excellent suggestion to use the 13mm boss. I think that's what we'll do. Also, the position of the small hole in relation to the butterfly is a very important point. I'll have a close look to make sure I get it right.
Just ordered a 3mm hose tail from ebay.au. This one has a standard metric M5x0.8 male thread, which leaves plenty of room inside the 13mm boss.

And yes: I was convinced that all threads were UNC or UNF, but just as John and M. say, it looks as if they've used metric threads. What I thought was a 5/16 nut on the throttle spindle appears to be a 8mm x 1mm metric fine thread. This remains to be confirmed, though. They are very similar; the M8x1mm pitch is almost exactly the same as for 5/16 UNF (25.4 instead of 24 threads per inch).

Br,
Einar

Busted Syncro

16th June 2016, 08:58 AM

G'day Einar,

Yes the Solex is all metric thread, designed in France and in 1925 Gordon Richards started manufacturing Solex in England. All still metric.

The spindle thread is M8 x 1.00. I would run a full nut with lubrication over the threads to clean them up. Also be careful when starting the nut because of the two flats. It's easy to cross up the threads.

The use of the Boss with the 1.5mm hole into the throat will be 20mm below the original vacuum port and is well clear of the throttle plate. It will be a compromise however, in the circumstance it's the best you can do.

Chris

EISTO

21st June 2016, 05:18 AM

Hi!

The carburetor has now had a thorough clean, involving thinner, red ethanol, ultrasonic cleaning bath, brushing, rubbing, swearing....you name it. It still REEKS of petrol, though :). There was an incredible amount of copper/aluminium rust and grit inside the body, but I managed to clean out most of it and used compressed air to make sure the ports were not blocked.

Chris: by veeeery careful drilling with a 5mm drill bit we managed to remove the remains of the old screwed union and the olive . We then cleaned up the old threads and inserted a hosetail with M6 thread. Phew! Did exactly as you said and carefully cleaned up the M8x1 threads on the throttle spindle and starter valve lever with a new nut. The nut enters quite easily now.

I noticed that -at closed position- the throttle butterfly more or less blocks the ports for the vacuum system. It clears the ports by around 1mm. I've assembled the spindle exactly the way it was, so I guess it's supposed to be that way.

Of course, while taking apart the starter valve, I managed to lose the 5mm ball, but luckily, I found a replacement.

It's becoming more and more apparent that some ham-fisted DIY'er with undeserved self confidence has given the carb a hard time using the wrong tools. I discovered that the emulsion tube is broken, and I guess there's nothing we can do about it. Perhaps the carb will have to be replaced anyway, but we'll at least test it before we write it off.

/E

Busted Syncro

21st June 2016, 06:08 PM

G'day Einar,

Gee you have been busy. Good work to reuse the M6 port. When it comes to old Series Landrover, ingenuity is the key and a never give up attitude.

The throttle plate position depends on the idle slow speed adjustment screw and will just clear the vacuum port depending on the idle speed set.

Bad luck with the emulsion tube. However can you post a picture of the broken bits for us. Is it the brass tube or the diecast spraying bridge or the spraying orificies bit?.

Chris

EISTO

22nd June 2016, 09:00 PM

Hi Chris,
Yep, once you get started it's too fun to stop. I love this type of project; for every challenge there is the additional satisfaction of solving the problem :)

Attached are pictures of the emulsion tube and spraying bridge (choke tube removed). My description wasn't that accurate, and to be honest I'm not exactly sure which role these parts play. I''ve given myself the homework of researching this.
Anyway, it's the spraying bridge that's broken. The emulsion tube is intact, and the correction jet is of course missing. I guess the issue is how to get hold of a correction jet and find out how to attach it to the broken spraying bridge.

Einar

Busted Syncro

23rd June 2016, 05:53 AM

G"day Einar,

Thank you for the photo's.

It's bad news and good news.
The broken spraying orifice is removable from the spraying bridge and is replaceable.
The bottom of this tube is a taper fit into the spraying bridge.

However, it could be difficult or easy to remove so only use light twisting and pulling otherwise you may break the spraying bridge. Maybe WD40 here as well!!!

You need to find another Solex to use for spare parts. Europe was popular for Solex so maybe wrecking yards might turn up something.

Hope this helps
Chris

EISTO

25th June 2016, 09:21 AM

Hi!
Unfortunately, Norway was never big on Land Rovers, and the odds that you'd find an old series car hidden away in some scrapyard, are unfortunately pretty slim.
Spoke to my cousin (the owner) and we decided to take our chances on a custom repair. We chickened out on removing the spraying orifice/column despite soaking it in WD-40 overnight. It didn't budge and I couldn't risk using any force.

It took a day or two to think this through and try to find a patent that could (potentially) solve the problem. This is what we came up with:

We had to find something -preferably made of metal- that could serve as an airtight coupling between the broken cast spraying orifice and the jet itself. It turned out we already had a new jet, as it was included in the solex repair kit.

Then I came across some copper support inserts for copper tube compression fittings. See Attached pictures. They are about 30mm long and 10mm in diameter. The wall is just 0.8mm thick, and they are perfect fit for the diecast column. Had to use a bit of force to press it on, and there's no visible gap.

The jet has a standard 6mm thread. We took a 6mm nut, filed it down to about 8.5mm in diameter using a battery drill and a file, and then pressed it into the copper insert, adjusting the height correctly. And that was that. A drop or two of loctite will make sure it's airtight.

Since the copper tube is slightly larger in diameter than the old (intact) spraying column, it reduces the effective cross section of the choke tube (not mounted in pictures). A guesstimate says 1-3%, depending on where you measure. Hopefully, this doesn't affect performance significantly.

The carb will be installed in a couple of weeks (the car is 1500 miles away) and I can't wait to see if it works.
I'll keep you updated :)

Einar

Busted Syncro

25th June 2016, 10:13 AM

G'day Einar,

Very nice solution and thank you for posting it.

Couple of things to note.

Don't use a gasket under the air correction jet. The seal that you want is between the brass emulsion tube and the air correction jet. Also as you are aware of, don't over tighten the jet.

I note it is 180 (1.8mm hole). This will give you a slightly richer mixture over approx. 2000 rpm.

The sight decrease in air flow can be compensated in selecting a smaller main jet however, the jet sizes are only 0.05 mm apart in diameter so size is very critical regarding fuel consumption.
For a 26mm choke tube the standard main jet is 120 (1.20mm hole). So in your beautiful and cold country the original main jet is maybe what to use.
See how it goes regarding fuel consumption. :D

Also the pilot jet must have a gap between the brass hex and the casting. The seal here is the tip (nose) of the jet and the casting. You can check that the jet is seating on the nose by using a gas lighter to put carbon on the nose and seating it and noting the contact ring.

All good
Chris

EISTO

27th June 2016, 12:45 AM

Deleted

EISTO

27th June 2016, 12:50 AM

Hi Chris!
Thanks for those kind words about Norway :). Not to mention your observations about the jets.
After reading your post we've made a small gasket to fit between the correction jet and the emulsion tube.
We also had a closer look at all the jets and noticed that 3 out of 5 (including the correction jet) are a different size compared to the old ones. The Bearmach repair set we've used is supposed to be for the Series 2A 2.25L, but there are some strange differences.
These are the old vs. replacement jet sizes:

Part No............Name..........................Origin al size...........Replacement size
__________________________________________________ ____________
46...................Main jet.......................126..................... .150
39...................Accelerator pump jet.....50........................60
53...................Starter jet....................145......................14 5
51...................Pilot jet........................60..................... ...60
49...................Correction jet................?.........................180

The correction jet is specified as being 175 or 185 in the parts catalogue. Shouldn't 180 then be OK?
Our new main jet is far to big, the parts catalogue says 125 or 135. The pump jet is 65 according to the parts catalogue...

For the main/pump jets, we an reuse the old ones until we get the correct sizes. We're not going to cross the Atacama in this one, so I guess the standard sizes are ok.
Do you know of any good online shops that sell them?

Thanks,
Einar

Busted Syncro

28th June 2016, 09:25 AM

G'day Einar,

Firstly there is another thread that you need to read regarding the Solex B40 PAIO.
"Series Land Rover Sub Forum Series III - fuel problems."
I have posted detailed and accurate information about the Solex B40 there.
(You have to check the original jet size holes with ground precision drill shanks)

(Note.When I get a chance I will PM the site administrator and see if we can put these posts into a normal thread under this sticky.)

Also I have mislead you regarding the seal between the Air correction Jet and the Emulsion tube by using the wrong wording.
There is no seal required because it is metal to metal contact which effectively acts as a seal.
However, thinking about your situation maybe a seal is required because you have repaired the spraying orifice and alignment could be a problem. I suggest you use a cigarette lighter to put carbon on the Air Correction jet and check the contact pattern to the emulsion tube first. Then maybe a thin (1mm) O ring could be used if required.

Now regarding the jet sizes. Main jet is 150 as supplied by aftermarket.
OMG :o. That's not a jet that's a hose!!!!.
It is 480 sizes larger than 126. They go in 0.05mm increments and 0.025mm increments for main jets. Very hard to measure.!
I can see because of the cold climate 126 (1.26mm hole) is needed.
Use the original main jet and see how your fuel consumption goes.

The air correction jet is normally 185. However, 180 will be OK as again because of the cold air, will give a slightly richer mixture.

I would use the original accelerator pump jet.

Because the Pilot Jet is aftermarket with the thick hex it may not seat on the nose of the jet.
Use the original jet if it has a thin hex.
There must be a gap between the brass hex and the casting.

With aftermarket you have to check every detail against the original part and if different ASK WHY??!!!!!
Hope this helps

Chris

EISTO

29th June 2016, 07:57 PM

Chris: A sincere thanks for all your help. I totally agree that these posts should be moved to a different thread. It would keep this one more compact and filled with general information rather than our specific issues.

We have ordered new jets with specific requests as to sizes. I guess we'll have to take this step by step. First goal is to get the engine started, then we can start diagnosing the carb to see if we need to make adjustments to the jet sizes and determine whether our MacGyver-fix for the emulsion tube works.

Best regards,
Einar and Dag

GeorgeTheLandy

26th June 2022, 11:43 PM

Good day to all and thanks for sharing the threads so far. I am in a bit of a pickle as I have rebuilt my Solex B40 PA 10-6 and the engine is not running as it should. I looked for a manual to help me understand which of the jets do what but could not see one. I did find a couple of rebuild kits and managed to piece together the new parts needed to rebuild it but now i have white smoke coming out the exhaust and not sure which screw/jet is the idle and which is which for that matter. I did count the revolutions before disassembling and matched them but something is not great. Any help on finding a manual to show what it what and what adjustment is needed would be champion...Thanks in advance for the help. I added a video and the clanging sound is the exhaust bracket not the engine so please discount that if you watch it.
Some questions:
1. What is the green electrical wire that connects to a lug on the carb in photo's 04 and 05? Where it connects on the carb has come loose and there seems to be a small ceramic collar with a spring inside.
2. Where is the mixture screw? I think it is the one located behind the throttle lever and in front of the vacuum hose in photo's 02 and 03.
3. Also the float valve I used in the rebuild had a slightly larger hole in it than the original, only by about a mm but still larger in comparison, will this have affected anything?

Before I rebuilt it the engine ran clear with no smoke now i have white smoke coming out the exhaust, does that mean it's not getting enough fuel?

Thanks
Laters
G

https://youtu.be/_n-4mjuZ6GM

Photo 01
179441

Photo 02
179444

Photo 03
179445

Photo 04
179446

Photo 05
179447

Photo 06
179448

GeorgeTheLandy

27th June 2022, 12:16 AM

Of course it is, how embarassing :D

I'm getting a bit confused by the figure in my manual. There's something strange here. I decided to remove the tube, and there's no trace of an olive or screwed union (16 & 17 in below figure). The tube seems as if it was just pressed into the carb body. The hole is the same ID as the tube.
My guess is that the screwed union has snapped just like Chris mentioned, and that what remains is so rusted that it just looks like grit.

I guess Plan B is to either try to clean out the remains of the union screw or drill/thread a hole and fit the tube with a larger diameter union.....

Einar Can anyone tell me how to set the mixture control screw on the solex b4 pa 10-6 How far should I screw it in? Does anyone know where the image shown in this thread of the exploded solex view comes from along with the detailed parts. I am trying to identify what does what and it would be really helpful?
With regard to the copper tube, there should be a brass collar that allows it to fit to the carb, it comes from the distributor if memory serves me right.
G

GeorgeTheLandy

27th June 2022, 04:05 AM

Can anyone tell me how to set the mixture control screw on the solex b4 pa 10-6 How far should I screw it in? Does anyone know where the image shown in this thread of the exploded solex view comes from along with the detailed parts. I am trying to identify what does what and it would be really helpful?
With regard to the copper tube, there should be a brass collar that allows it to fit to the carb, it comes from the distributor if memory serves me right.
G
Okay, so I have adjusted the mixture screw according to the instructions in the manual, essentially screw all the way in, then screw out 1.5 turns and adjust while engine is running to correct idle. What happens now is when I push the throttle the engine stalls. The white smoke from the exhaust has gone, but now it stalls and still does not run smoothly.
Any thoughts?
Thanks
G
https://www.youtube.com/watch?v=e9OTIgAGlMk

jules reynolds

29th April 2023, 09:00 AM

Hello
can anyone tell me if the circled and arrowed parts of the Solex carburettor are removable and if so what’s the best way to do this.

I am wanting to gently sand the base to ensure a flat service

thanks
Julian
Christchurch
NZ

B.S.F.

29th April 2023, 11:02 AM

Only remove the tube if you think its absolutely necessary. It can be very brittle and is easy to break.
Use one of the cover screws in place of the jet. Grip it with pliers and without wriggling or twisting pull straight up
and hope someone hasn't tried it before you, damaged it and used Araldite.
To remove the choke tube remove the grub screw and lift the tube out.