Official Dual Carburetor How To Thread

[oprn]

Thanks again for the reply.
Ok I won't rule out the Weber 40s yet. And no I am trying to avoid two single barrel carbs due to the impossibility (in my opinion granted) of ever getting the mixture the same on those two adjacent cylinders due to one cylinder leading and one lagging in the timing sequence. VW did make it work - kind of but, it is not ideal.

Are the Weber copies worth the savings or is it false economy?

The major reason for the fixation on cold weather running is my involvement with a form of ice racing here in our long northern winters that are held right down to -30. Neither my sand rail nor this beach buggy will run consistently enough to be usable presently. Lack of thermostats being the main culprit there. I could heat the cargo trailer I haul them in to help the starting issue with the Webers though. The sand rail with it's stock Solex will start right down to -35 instantly with no block heater. Just will not make a smooth transition to fully warmed and running right without a thermostat.

Oh for a complete type 4 FI system and the parts to keep it running for the next 10 years! Dreamer I know!

Thanks again for taking valuable time out of your day for my questions. Merv

[AlteWagen]

The Gen III HPMX seem to be doing OK from what I hear. The gen I carbs had all the cold circuit stuff inside with the block off plate outside and they seemed to leak causing all kinds of tuning issues. The second and third gen versions do not have any cold circuit stuff so that is no longer a potential issue.

Still need to clean them out and set the floats as with all new carbs. The "made in the usa" flat back webers are problematic due to faulty machine work, I would avoid these at all cost

Some have reported good luck with the $100 FAJS weber clones on ebay. Not sure if they have the cold start innards but they are priced about the same as a core carb these days. You can order the jets you need for your specs too.

http://www.ebay.com/itm/fajs-40IDF-Carb-Carburetor...mp;vxp=mtr

I see they are also selling a 40 IDA TB now too, maybe your FI dreams can become a reality with a mega squirt CPU and some CB manifolds. A bit pricey but when is FI cheap?


http://www.cbperformance.com/product-p/3161.htm

http://www.ebay.com/itm/40IDA-Throttle-Bodies-repl...SwImRYUoF1
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Grapes of Wrath $200 Engine Rebuild
Official Dual Carb Thread
Cylinder Head Quick Reference Sheet

[oprn]

Hmmm... Ya looks like a bit of a "buyer beware" market out there.

Looked up the CB injection - yikes! A bit pricey for a weekend fun buggy but no doubt good stuff if you are dead serious about FI.

I do have a complete and "running fine 8 years ago" stock FI system in a '70 411 but can't bring myself to part out a complete and restorable car just for that. Call me a sentimental fool! And what to do if one of the components on the original VW system fails...

Thanks for the ideas, I have some time till spring to decide yet.

Merv

[Warren43]

Wondering what majority prefers when venting dual Dellortos. I've read that it is only necessary to vent the drivers side carb but some prefer to vent both. Any thoughts?

[Vicgrcs]

[MarkWard]

We have a Type 2 with dual H40-44 EIS solex carbs in the shop. We ordered two overhaul kits. When the van sits, the needle valves are now sticking shut. The stock mechanical pump is not enough to overcome the sticking needle valves. The kits are from Radke Services LLC. I'd use the original needle and seat, but the two I removed don't match.

Any ideas? Are these kits poor quality? Do I need to put in an electric pump to overcome the needle valves? Where can I get a quality needle and seat for these? Thank you. mark
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[AlteWagen]

[AlteWagen]

[MarkWard]

Thank you. IMC still sells needle and seats for the stock PICT carbs. From memory, they look identical. Ordered a pair and will try again with these parts. I'll update.
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[AlteWagen]

Mark, any luck with the new needle and seats?


Vicgrcs, I checked my stash of old carbs and looks like I sold all of my extra kadud parts. Good luck with your search
_________________
Grapes of Wrath $200 Engine Rebuild
Official Dual Carb Thread
Cylinder Head Quick Reference Sheet

[MarkWard]

I forgot to update. I got the needle and seats from IMC. Nothing unique about them and they did not match the picture in the IMC catalog. I installed them, but also decided to drain the fuel tank and fill with non alcohol fuel. So far so good. The van did not leave because the brake pedal went to the floor when we went to road test it. Single stage master with disc brakes all 4 corners. L/R caliper was leaking. New caliper came today and we bought a dual stage master to retrofit into the 58. Thank you. mark


P.S. After I got the carbs synced and shut off the engine, the fuel pump started weaping fuel out the vent, so I put a new fuel pump on it. I wonder if the regular fuel had an affect on the diaphragm after being exposed to alcohol fuel? Mark
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[JustBuggy]

You might want to change your oil too.

[mark tucker]

I saw something about venting the driver side carb.....above a few post's...both of mine are out in the breezzee I wonder if thats good enough venting as for mark wards thingy, dead pumps are some what problematic. old pumps die, pumps that see limited usage and dry put seem to fail also....also all the new gass&additives in them may also be hard on the diafram., or just using a fuel system/injector/carb cleaner can kill them.when ever you do a spring tyme cleanup and use some sort of carb/fuel system cleaner(witch is a very good idea if your car isant a daily driver) always run all of it out of the tank and new fresh gas in. (dont dose it and let it set there in the tank&carbs) put it in with a 3/4 -full tank,drive around however you wish, but try to use that tank of fuel up in a week or so and refill , Ive often wondered about the rubber coumpound the china kits&carbs have in them as well as old nos kits or old carbs that were properly presereved.can they handle the new cleaners? probably not for long so clean&refill. I had 3 bottels of diferent additive's all with about 1" left in them....yup I mixed them to consolidate..... a month or 2 later I noticed the bottle was melting and all deformed.......now befor you start chewing my ass as usual for spelling and mixing additives....when you add a additive to your tank do you know what the fuel had in it to start with????? thus use the cleaner and then run it out and refill..if you store your car use some STABILL in the fuel, dont scrimp use the proper amount, and then when it's tyme to get it out for a run add some fuel system cleaner and go have fun. and run more than 1 fuel filter, one befor the pump and one after the pump. that way nutten gets to the pump to effit up and if the pump takes a shit on it's own or from new/old gas, it catches it befor it gets to your carbs and realy gives you headaches.there's my 3 centavos on fuel systems& issues. if you dont like my spellen dont use any filters.

[oprn]

Mark! I understood your post!

This stale gas issue may be overstated at times. I went to start up a '92 Jetta last summer that had been sitting for 6 years with 1/2 tank of fuel in it that stunk to high heaven. I thought I would have to drain the fuel system and tank and refill it. Nope - fired up on the second compression and ran the tank out without missing a beat!

I bought a Yamaha bike off a buddy who told me to always use fuel stabilizer as the bike would not start if the gas was more than 2 weeks old. Well the stabilizer didn't change anything, it still won't start after it's sat for a few days unless you drain the carb first. Now get this... last fall I filled up the Yamaha and the Honda out of the same gas can no stabilizer and didn't try to start them until 3 weeks ago. I had a horrible time getting the Yamaha to run but the Honda fired right off!

Some engines may be just fussy.

[oprn]

On a carb related issue, I am reading on here about fuel pressures and regulators. It seems different opinions exist on what is the proper fuel pressure and how to achieve that.

I have an engine with Kadrons presently that ran rich and poorly with horrible fuel economy. Reading about fuel pressure got me thinking that I may have to address that issue. I admit to not bothering to check what it was running at, just went ahead and made a change. While waiting for a regulator to arrive I just installed a check valve with a cracking pressure of 1 psi in a line from the carb tee back to the inlet of the fuel pump.(I don't comprehend the need to take it all the way back to the tank.) The fuel pressure is now steady at 0.9 psi and the engine already runs night and day better even just sitting on the floor!

The only issue so far was that on one start up one of the carbs had the float stick shut and took a couple raps with a screwdriver handle to fill up with gas. I may need to shim the check valve spring to hold back a bit more pressure. I am anxious to get the engine back in the Buggy now and see how it drives!

[oprn]

I just discovered the reason that car companies use a return line all the way back to the tank. On start up with empty fuel lines the air just keeps recirculating and air locks the fuel pump. Total pain to get purged out!

Once the system is air bubble free you can just discharge the access back into the pump inlet no problem.

[modok]

Yes indeed. When you shut off the engine the carbs may heat up, and that boils some or, even all, the gas out of the carb, or even the fuel lines. Turns out the air flowing through the carb, and the fuel flowing through the lines is what cools them. I think it is WORSE with gas today, as it contains a a lot more "paint thinner" type stuff now than it did 20-30 year ago, but modern cars can handle that.

Makes sense to have the pump and regulator WAY back right by the fuel tank so they don't ever get hot. This is true for MANY classic cars, not VW specific at all.

The design of the kadrons is not very different from other solex carbs that handle 3-4 psi fuel pressure. Perhaps the needle and seats are poor quality, or there is a vibration problem? It is ODD to have a carburetor that can't handle 3 psi

[oprn]

I just checked my stock VW pump and it is putting out about 4.5 psi. Not sure exactly as the gauge needle is somewhat below zero at rest. For that small amount I could shim up the pump and likely still have enough volume. I would rather regulate it though.

[oprn]

I just confirmed tonight that it is not physically possible to adjust the left idle mixture screw on my Kadrons with the engine in the buggy!

Very frustrating indeed!

[mark tucker]