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Weber 32/36 DGAV 33B Carb. Questions

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MG Larry Avatar
MG Larry Larry Asero
Basking Ridge, New Jersey, USA   usa
1973 MG MGB
I have a Weber 32/36 DGAV carb. I want to check the float hight and adjust the idle and mixture and check the strainer for crud. Where is the idle screw and mixture screw? I have the Haynes Weber Carb manual but have not studied it yet. The diagram looks confusing. Any advice on adjusting or just cleaning this carb. I am trying to resolve a stalling problem. I can't seem to find any adjustment screws. I think there is one pointing towards the valve cover which seems akward to get to. I guess since these are after-market carbs the adjusting screws could be in an inconvenient place?

Weber 32 36 33 B DVAG.jpg    44.7 KB
Weber 32 36 33 B DVAG.jpg

peted Avatar
peted Peter D
Charleston, SC, USA   usa
You've found the idle mixture svreww and yes, it is in an inconvenient location.
Use a stubby screwdriver and wear a thin cotton glove to adjust it.
The idle speed screw is most easily reached with a wrench.
There are good reasons not to mess with these adjustment before having done the following:

The first rule of carb tuning is to be systematic and patient.
Start with checking and adjusting your ignition timing and service the distributor and maybe replace points.
Make sure your spark plugs are in good condition and check for spark.
Check fuel filter and make sure that your fuel pump is working properly.
Check and replace air filter if necessary.
Look for vacuum leaks.
Look some more for vacuum leaks.

After all that is done you may start looking at the carb itself.
Read everything you can find about your carb and keep notes about your adjustments.

If the car has been running fine with the same carb and jetting before and all the above has not worked, simply servicing the carb (from simple cleaning to complete rebuilt, depending on the condition of the carb) should suffice.
If not, the carb needs to be tuned for your engine.
That job cannot be performed without everything else in perfect working order.


stephencs Avatar
LAFAYETTE, ky, USA   usa
Pete is correct i have the weber 32/36 dgav myself and if you havn't checked the other items than don't touch the carb i made that mistake after purchasing my B and my problem ended up being a timing chain and after changing the timing chain I then had to take the carb back to factory setting and start again check you normal stuff your plugs, plug wires, and every thing else pete said and if that doesn't work look at the carb

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Paul J Avatar
Locust Grove, ok, USA   usa
I also agree with Peter! Most problems on poor MG engine performance, are ignition related and vacuum related. Timing could be off, distributor shaft could have a wobble throwing point settings off, vacuum leak etc. Get those settings on the money before you touch the carb or the fuel system. I'm not a fan of the Weber 32/36 carb, as it doesn't pull the performance out of the engine it should over the complete RPM spectrum, but in all reality, it is pretty much bullet proof and usually a change in jet size is all that's necessary for major adjustment, but that's usually an initial thing when first installed. Other than that, a needed float adjustment or idle mixture adjustment is possible.

Edited 1 time(s). Last edit at 2010-03-22 07:10 AM by Paul J.

Bob Agar Avatar
Bob Agar Robert Agar
Green Valley, AZ, USA   usa
1953 MG TD "Myrtle Anne"
1974 MG MGB "The Mistress"
And since nobody else mentioned it, that air filter element should be treated with the K&N air filter oil which turns it pink.

comart45 Avatar
comart45 Peter Cummins
Lansing,MI, USA   usa
To make life much easier in the future, reverse the positioning of the carb so you can access the adjustment screws in a humane position.





carb in this photo is not reversed yet

carb in this photo is not reversed yet

MG Larry Avatar
MG Larry Larry Asero
Basking Ridge, New Jersey, USA   usa
1973 MG MGB
Peter thanks. And the rest of the posts too. Beautiful pictures and engine! I'll be studying them this weekend. I just want to check for crud in the float bowl and strainer screen first.

I'll then make sure that the settings are per the Haynes manual I have.

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MG Larry Avatar
MG Larry Larry Asero
Basking Ridge, New Jersey, USA   usa
1973 MG MGB
I took the strainer off the carb and it was fairly crapped up. I ran the car without the filter and it seemed to run better. It goes longer without stalling. It did eventually stall so it is still undrivable except down my block. If the carb is really dirty will this cause constant stalling problems? I will check the float bowl this weekend.

Is there a carb rebuilder that anyone recommends?

James74 James D
beach, VA, USA   usa
1978 MG MGB "The Bee"
Larry likely your idle jet is clogged. I would recommend taking it off and letting it soak in fuel for a day. Then rebuild it, The kit is about $15.00 at weber carburetors direct. Should be a fairly straightforward rebuild.

Compressed air is needed to blow out the small passageways after the soak...

78..Bee, Leyland A/C (removed), Saturn 95 amp Alternator, Wire Wheels, Lumenition ignition, Weber 32/36, Four speed.

Edited 1 time(s). Last edit at 2010-03-24 10:47 PM by James74.

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