The following information was provided by BigJim5551212, a long time group member, assistant manager, and…

“The Official Weber Supplier for the 720 Group”

 www.overseas-auto.com  http://groups.msn.com/webersandstuff

Weber Carburetors for Nissan Trucks

A Short History

The Weber DGV Series and its derivatives were first used by Ford of Europe in about 1969. It was developed for the Capri series cars that had engines from 1.3 to 2.8 liters. Its heritage dates back the DCD series that came out in the early 1960’s. Today, it is used as an aftermarket carburetor on all kinds of applications from old BMW’s to Nissans, to Jeeps, to VW’s. This carburetor has great tuning potential and is easy to repair and rebuild. The carburetors are plentiful new and used and with a little digging you will find one in your price category.

The Tips and Tricks

-If you buy a used Weber, make sure all the parts are there, like the choke mechanism and the pump arm and cover

-Remember, when putting a bigger or higher flow carburetor on, it will magnify engine problems.

-When you install the carburetor, make sure the fuel pressure is 3.5 psi or less

-Jetting- The magic to the Weber is the jetting, you can tune it for anything. Primary idle jets should be set about 60, but you should get a 55 and 65 so you can test for hesitation and economy. Main Jets, should be around 140 on both barrels but you should try smaller ones for economy and emissions. You will find if you go too small there will be hesitation and more “hissing” from the carburetor. Remember, the idle jet controls the engine up to about 2500-3000 rpm. If you have a cam and headers, you may have to go larger on the idle jet. Maybe even as large as 70

-Other factors. Ignition timing-make sure your distributor is advancing properly. Lots of Nissan distributors have the weight seize up. They need to be freed up. Make sure there is enough initial advance. If there is not enough, then the acceleration will be slow. Make sure the cap, rotor and wires and plugs are in good condition. If you have a multimeter, you can check the wires. No more than 10,000 ohms.

Throttle Shaft Wear - Using our Throttle Shaft Bearing kit, this can rescue many Weber DGV series from the top shelf or worse still - the used metal bin.

  

The Carburetors

32/36 DGV Manual Choke 26mm primary 27mm secondary venturi

32/36 DGAV Water or Electric Choke 26mm primary 27mm secondary venturi

38 DGAS Water or Electric Choke 27mm venturis Synchronous opening

Adapter Plates

99004.300 L20B, L16, L18. One piece adapter. Can only be used on a manifold that has no holes around mounting studs

99004.333 Z20, Z22, L20B, L16, L18. Two piece adapter, works best, costs a bit more

99004.336 Z24 adapter. One piece adapter

Air Filters

DGV250 2.5” Tall, 6.75” x 2.5” Oil Wetted Cotton style filter (this filter has many part numbers from different organizations

A person can put together his own kit or buy one that has everything in one box. The only problem with the boxed kit, is that for some applications, you have to be careful with what you order as some kits for other cars may actually be more suitable for what you are doing.

Manifold Conversions

Offenhauser Sales, makes a couple manifolds for the Z22 and Z24, but I don’t think a person will gain much. They will not hurt, but with the design from Offy, the main system comes in earlier and that defeats some of the ideas in the Weber. However, there is a manifold for the L20B from Cannon that does make a difference. They say 5 hp at 4500 rpm. The other advantage to this manifold is that you can put a bigger filter on.

Rebuilding a Used Weber

Congratulations on finding a used DGV or DGAV Weber. You have found it is complete, and all the external parts appear to be there, but the carburetor is totally black and covered with grease. You should get a box now that has a bottom that will not fall apart or lose parts. Start by taking the outside parts off, throttle shaft parts, pump mechanism, electric choke, then the choke housing, lid of the carburetor, jets, float needle valve and so on. When you get to a bare carburetor with the throttle shaft and butterfly still attached, examine the slop carefully in both barrels. If the secondary is fine, then leave it alone. If the primary has a sloppy shaft, remove the screws carefully that hold the butterfly in and remove the butterfly. Then slide the shaft out. You will need to get Overseas Distributing’s bearing kit when you put it back together. Watch out for the springs. The exploded diagram in the repair kit will show the way it all goes together. On the carburetor lid, do not remove the screws for the choke plates. Just leave everything as it is, unless there is some issue that you need to take care of. It is time to clean the carburetor. The cleaner that I use currently is Castrol Super Clean. I use it undiluted. It will take all the grease off. You can let it soak for a couple hours or overnight. Be careful it is strong. You have to get a small brush and when you rinse the carburetor with hot water afterwards, have a small brush to get in all the nooks and crannies. You do not want the acid working any more. Let the carburetor dry and then blow it all out with compressed air. Make sure you have cleaned all your other parts as well. If you clean the choke housing, take the diaphragm out and set it aside. It does not usually wear out, but you don’t want to have it in the cleaner.

After everything is cleaned and dry, you can paint the carburetor with clear paint from Home Depot, it is a matte finish. Now, have all your parts lined up and have your rebuild kit figured to see where all the parts go. You can now put it all back together. You should not have any new parts left over. There will be instructions for float level in the kit. If you use the bearing kit for the throttle shaft, it is very easy to install, there are little plastic bushings that are in the carburetor. Remove them and substitute the new bearings for them. You should use new screws and have the threads chased in the throttle shaft.

Repair Kits

Basic kit: Contains all gaskets, needle valve, internal fuel filter, pump diaphragm

Power Valve Kit: Has new Power Valve Diaphragm

Bearing Kit: 2 throttle shaft bearings with 2 throttle plate screws

Other parts are all available, springs, washers, screws, linkage pieces, choke elements etc

Proper Design Top Cover Gasket: In the past few years, Weber has been putting an incorrect Top Cover Gasket in their carburetors and their repair kits. This leads to problems on vehicles that are going off road and also that are in high G situations, like race cars. The proper gasket that we have completely seals the float bowl from the air corrector jets. We have this gasket available for $5 plus shipping.

 

Used Carburetor Guide

Here is my guide again for people looking for Used Weber Carbs at the JY or on Ebay

Ok, for all you guys that hunt JY's. If you are going to look for a Weber Carb, this is what you should look for. First I will mark the cars and trucks, and then the model of carbs. I will be pleased to tell you if the carb is worthwhile if you find something else. I have the repair kits available. These vehicles had Webers as conversions only. No car in the US or Canada came factory with the DGV or DGAV

Vehicles
BMW - 2002 with 2 barrel manifolds (best place to find a used Weber)

Datsun/Nissan - carbureted trucks and cars pre 1986 L, Z, A, E series engines
Jeep-CJ, Wrangler with 258 motor

Mazda - B2600, B2200 trucks. Most cars had people that didn’t care about performance other than rotaries
Mitsubishi/Dodge D50 - carbureted pickups, Raiders, Colt front drives
Opel - Opel GT

Suzuki – 1300 Samurai

Toyota - Corolla pre 87, Tercel pre 91, Celica-pre 81, Land Cruiser 80's and earlier, Pickups pre-88
Volvo-non fuel injection cars (144, 122)
Jeep-CJ, Wrangler with 258 (4.2) and 2.5 motor
Ford - Old Cortina mark 1 (1967?)

Carbs to use
32/36 DGV (manual choke), 32/36 DGAV (auto choke), 32 DGAV, 32 DGV
38 DGAS Maximum performance, mileage will be lower
36 DCD, 28/36 DCD

Questionable carbs
Holley 5200/Weber 32/36 DFAV - linkage reversed to DGV series, most Holleys have linkage that is not bolted on and some have non changeable idle jets, throttle shafts wear easy
Fiat Webers, DMSA series harder to get parts, linkage reversed, 1800 carbs will not fit adaptor
Renault Webers DIR series- same as Fiat

If you are handy, and have access to parts, the Renault and Fiat carbs will work OK

A big thank you to BigJim for all this great information!!!  Be sure to check with him for all your Weber needs.   TTR