Setting 34 PICT-3

[GavinHuart]

Thanks so much for all the replies chaps

@ Boxerulez & Retrovan - I've had a look at that ad of Bratjie's and will contact him about it a little later . Ideally, I'd love a brand new one just because . I have tried Midas and Goldwabegn this morning and neither stock 34 PICT-3's at all

I've tried ringing Forcecooled a moment ago but can't seem to get through at this hour. Will try later.

Thanks again, I really appreciate the feedback and I'll update with the progress

[slak]

Try volkspares as well Midas sell them under the Brosol name just tell the salesman u'r looking
for a beetle carburettor they don't usually know these cars so are not much help
or phone parts incorperated in edenvale they should have got one from them last year
but they are pricey

[GavinHuart]

I've spoken to forcecooled early this morning and he's kindly offered to have a look at this carb on Saturday although we don't know if it's fixable at all yet.

I've since managed to get hold of Parts Inc in Meadowdale (thanks slak!) who have a Brosol 31-34 PICT-3 in stock. The sales guy is not sure if this carb will need the adaptor plate to fit the 1600 Dual Port manifold. I'm not at all clued up on carbs or this cryptic sounding adaptor plate. Anyone who's used this brand of carb, please could you enlighten me ; will I need an adaptor plate (they don't have stock of that)? Is it a good carb?

Ta muchly!

[fig]

If the new carb's a 31PICT and you're fitting it to a twin port engine, you'll need the adaptor (it comes with the carb). If it's a 34PICT then no adaptor needed for a twinport. If you put a 34PICT on a single port engine then you need the adaptor again, but fitted upside down.

Very often, a well rebuilt original Solex carb is better than a new Brosol. Also, some of the Brosols that have found their way here are made for alcohol fuel only and you can't get them to run right at all. If you do buyb a new Brosol, I suggest you transfer all the jets from your old carb to the new before you start.

[GavinHuart]

Thanks fig, all noted . Quick question, is the procedure for setting up a 31 PICT the same as the 34 PICT - ... fast idle screw set and left alone, small screw seated and then unscrewed but 1,5 - 2,5 turns... and so on?

[fig]

Thanks fig, all noted . Quick question, is the procedure for setting up a 31 PICT the same as the 34 PICT - ... fast idle screw set and left alone, small screw seated and then unscrewed but 1,5 - 2,5 turns... and so on?

Yes. Only the 28 and 30PICT carbs had the one-screw adjustment.

[GavinHuart]

I received a call back from Van Den Brink yesterday late afternoon and they have brand new Brosol 31 PICT's fitted with the adaptor plate (as fig mentioned above). Their price was pretty reasonable and I couldn't resist so I shot there after work to get one. The owner's son was there and was extremely helpful. He explained that they fit these carbs to all their cars as standard and they've never had any comebacks. I wanted to try fit it last night but I ran out of time and light so I'll attempt it this afternoon or first thing Saturday. Apparently they come preset from the factory but a wee bit of adjusting might be needed due to our climate etc. They have also offered to set it up free of charge should I not come right. I'd prefer to learn exactly how to do it so I'll connect it up and try fire up the motor before adjusting anything to check it is in fact working.

I've attached a diagram RE the jets that I have to swap across from the old to the new which I'll do before installing the carb to the manifold. Am I correct is saying it's numbers 17 and 34 on the diagram (marked in red) that need to be swapped or is there anything else that has to be transferred?

[GavinHuart]

... so I've stumbled upon this:

"The H30/31 Brosol carburettor can run the 1600cc engine OK, but it MUST be jetted correctly. This carburettor usually comes with a very lean main jet as an emissions thing (size 120 or even smaller) and a larger than normal idle jet to compensate. On a 1600cc the main jet should be a size 127.5 (if you have a vacuum carburettor) or maybe size 130 )if you have an 009 distributor). The idle jet should be a size 55, and power jet size 65.
The air correction jet size is very important when using a smaller carburetor on a larger engine. This jet stops the carburetor going over-rich at medium-high throttle. The 1600cc DP can flow more air than the 1600cc SP and smaller engines. And since higher airfow means a higher vacuum in the throat, this sucks in more fuel for a richer mixture, so you then have to enlarge the air correction jet to match the higher airflow. If not, the engine will run rich at medium-high throttle. The air correction jet should be about size 125."

- see picture - I gather number 9 on my previous post also then needs swapping?

This worries me as there's tamper-proof paint on some of the screw heads of the new carb. I'm going to lose my guarantee if I have to open it up .

Any thoughts?

[GavinHuart]

So here's some feedback:

After going through Rob and Dave's very in-depth write up on the Brosol H30/31, as well as many calls to and from Forcecooled (Bill you are an absolute legend and have been extremely helpful ) I managed to get the old carb off and the new one installed yesterday afternoon.

What I learned was that the Brosol H30/31 has to be re-jetted; particularly the Main Jet (as mentioned earlier in this thread). I started by checking out what the old Solex had in it so as to transfer some of the jets across. To my amazement, the Solex had also been incorrectly jetted for the engine.

Here are the stats of what is expected from Rob and Dave's Aircooled Pages for a 1600 Twin Port:
Main Jet: size 125 or 127.5
Air Correction Jet: size 125Z
Idle Jet: size 60 or 65 (usually a 55 will do for a Beetle but a larger one is needed for heavier Type 2)
Power Jet: size 55 (The new Brosol has a Power Jet and not my old Solex)

Here are the sizes of the jet that were in the old Solex:
Main Jet: size 130 (a little high)
Air correction: size 60Z (shockingly too small)
Idle Jet: 55
Power Jet: No Power Jet

Here are the sizes of the stock Brosol H30/31
Main Jet: size 120 (too small for 1600 Twin Port)
Air Correction: size 125Z (spot on according to R&D)
Idle Jet: size 65 (fine for a bus)
Power Jet: size 55

Not having any spare jets at home, I moved only the Main Jet from the old Solex across to the new carb. How on earth that Solex ran with a size 60Z Air Correction, God alone knows. Bill suggested that I move the old size 55 Idle Jet across too which I haven't done yet as R&D seem to think the bigger Idle Jet suits a heavier Type 2 better (considering most of your low-to-mid-range power is delivered by the idle jet).

I got it all connected up, fired her up and she roared to life ! A bit spluttery at first, but there was life . I then had a fiddle with the adjusting screws and what a difference to have an actual response from tweaking! I found that it idles very smoothly and quite high with the smaller screw unscrewed closer to 1,5 times than 2,5 with the larger screw out a similar amount of turns. That concurs with figs statement of unscrewing the small one that many times for places at our altitude. I then tweaked the bigger one to get a perfectly smooth, relatively high, idle. All of this was done with the engine fully warmed and the fast idle cam on it's lowest point. I went for a drive and there's no flat spot whatsoever and she just sounds far happier all round.

The only problem I've had, and it occurred a couple of times this morning on my way to work too, is that sometimes it'll cut out when coming to a complete stop at a traffic light, but only sometimes. What I've worked out is that it definitely cuts out when you brake hard to stop which suggests to me that perhaps there's an adjustment needed in with the float level? I could be wrong - just thinking out loud. Generally idles perfectly if you gradually slow down on a level road and come to a halt.

Any ideas of what could be causing it to cut out? (I have made a few very minor adjustments to the small screw so as to let it run a little higher in revs and then corrected that with the larger screw but it still stumbles when coming to a sharp halt).

[GavinHuart]

Further update -

The Brosol 31 PICT, coupled with "forcecooled's" assistance, is FANTASTIC! . Cutting out at idle is a result of too lean of a fuel mixture. The 1,5 turns out of the small screw needed a wee bit more as well as a fine tune of the larger one in lieu of and presto! Success!

I have noticed that even with the choke set to max, starting from cold she runs but does stumble a bit. It doesn't cut out and only really needs to drive a couple of meters in 1st and then it's good to go - probably a result of the blocked off heat risers, but the bus is going FAR better altogether so I'm extremely happy .

[Dawie]

Remember that often, info from American websites are irrelevant to "rest of the world". They had different carb and ignition settings to comply with emission rules of the time. They sometimes also had "dual vacuum distributors" with vacuum retard at idle. (Maybe that is why Impi says "who cares how it's done in California"?)

Jetting were different on US carbs. The 60Z aircorrection/emulsion tube unit and 130 mains is what came with most "rest of the world" 1600 beetle engines from 1972 onwards. The catch seems that it is not just a plain aircorrection jet, but a combination with the emulsion tube. Some US vehicles had an aircorrection/ emulsion tube of 75z or 80z, and used a 127.5 main. (According to some specs in various manuals). "Rest of the world" type 2 1600 engines from 1972 onwards had 125 main jets instead of the 130 on a beetle.

The 1971 year jetting was very different. On the first dual port upright engines VW used 145 mains and 130 airs for 1600 beetle and 140 mains/ 120 airs for 1600 kombis. (Remember that those years fuel was under 15 cents a litre, so consumption was not part of the equasion.) Driveability/ smoothness in temperatures far below freezing mattered more.

Think i must sometime post the various "rest of the world" jettings under "Guides", as the US info is misleading.

[GavinHuart]

Wow, thanks for this Dawie - very useful info.

Immediately a person starts to doubt themselves when you see a 60z increment air jet when it's "supposed" to be a 125z apparently. Then you think again and wonder how this "apparent" teeny air jet got in there in the first place.... there must be a reason for it?! Having said that, as you've mentioned, climate and altitude play significant roles in jetting and with us being as high up as we are in Jhb, the jet sizes I've gotten toare pretty close to spec according to what I've read (more or less).

I think it would be very useful to consolidate all the relevant info regarding jetting for SA altitudes and climates. I'd love to but I don't know enough about all the carbs and jets, only what I've learned on this specific one...

[eben]

What a lovely thread

[buggyfan]

Bump

[Retrobug]

Eish! Having simmilar issues!
Got allot to learn about these "simple" carbs!
Seems like the setting screws turn and turn with no difference to the result!
Or maybe I'm not noticing the changes!