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Help with rebuilding Weber 32/36 DGAV for 1973 Bavaria 3.0

Discussion in 'E3 "New 6", 2500, 2800, Bavaria 3.0S & 3.0Si (1968' started by Lionhead, Oct 4, 2013.

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    Lionhead

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    I am on the next step of the restoration of my Bavaria and ready to rebuild the dual weber 32/36 DGAV carbs, does anyone know what would be the best jet setup for these carbs to work smooth on this engine? I haven't opened the carbs yet so not sure whats inside. I've tried tuning with no success. I am buying not only the seals but needles, floats and jets as well to have them handy in case they need to be replaced. Any help, or your experience will be greatly appreciated.
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    Terry Sayther

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    These carbs are pretty straightforward to rebuild. I don't know why you'd replace floats and jets though. Floats are generally replaced only if they get a pin hole and leak fuel into the insides--then they get heavy and cant maintain the proper float level. Jets are only needed if changes to the jetting are needed----which they might be, but that's not so easily done. There used to be people around that knew what the proper jets would be. I would start with the searchable Roundel discs that Bentley Publishers putout a few years ago. They scanned all the old Roundels and put them on CDs. Quality linkage is the key to success with those carbs---the Jam Engineering kit is still the best. Then careful synchronization. Good luck---Terry
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    CRKrieger

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    I'm going to agree with Terry because to disagree would be foolhardy - but also because I've rebuilt those Webers. They're straightforward, simple, and probably need nothing but refreshing. They are sized right for that engine, so put them together and drive it. I have a Weber carb manual (Haynes Publishing Co.) around here somewhere that's pretty good. You can probably still buy it. What I remember about their jets is that there is no logical order for them. They apparently numbered the jets as they developed them, not by size. If your car runs OK now, just go with it.

    On the other hand, even if it's still a little rough, know that even the fine fuel-injected 3.5 liter derivatives of your 3.0 were on the ragged edge of 'lumpy'. The specific output and cam profiles of this engine generally meant that you could either have a slightly lumpy idle and great mid- and high-range performance or a slightly lumpy idle and crappy off-idle performance. So you're really shooting for the former. As long as it doesn't actually stall at idle ... you're good.
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    Satch SoSoCalifortified

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    Well, yes and no. Weber main jets are logically numbered in hundredths (thousandths?) of a millimeter, so a 100 has half the diameter of a 200. Air-correction jets, too. Some idle jets are similarly logical, but have minute air-correction holes in their sides; and the emulsion tubes that give sidedraft Webers their personality have no relative connections whatsoever. Those are the ones that make people swear that tuning Webers is a black art.

    Progressive downdraft Webers? Piece o' cake. Be a man and hang three DCOEs on there!
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    Lionhead

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    Thank you for all your help. I haven't had a chance to work on the carbs yet but will follow all your recommendations when I do so soon. The reason I've narrowed down the problem to the jets is because all adjustments so far have failed to provide a normal run. The top portion of the engine has been rebuilt, bottom is in good condition, timing belt checked, linkage verified as good, no vacuum leaks. I am sure I am missing something somewhere but I've taken the Bavaria to two different mechanics to work on the carbs with no real success.

    The problems: dieseling, continuos smell of gas, very poor gas mileage, stalling, jittery on acceleration. Overall not an enjoyable ride. Very unpredictable.

    One thing I did notice recently is the crankcase ventilator open, no hose in there. Would this affect the carbs running as they suppose to? Also one of the mechanics added an electric fuel pump hoping that this will help, with no real success.

    If you feel I am missing something here let me know, or maybe I should listen to Satch's advice and hang those DCOES!
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    CRKrieger

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    If these carbs haven't been thoroughly cleaned out during rebuilding, then there's a very good chance that's the problem. It doesn't take much to clog up some of those internal passages or emulsion tubes and make them run crappy.
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    Satch SoSoCalifortified

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    Well, if the crank-venting system is supposed to go to the intake manifold, and instead you have a huge air leak, there is no way to compensate with the carburetor(s)! :eek:

    CR's right about the carburetor body. We used to soak them (along with all their ancillary metal parts) in some mysterious carburetor cleaner that might have been used to dissolve Jimmy Hoffa; I don't know if the EPA will let you get away with this stuff anymore. Then comes the relationship-threatening step of running them through the dishwasher, followed immediately by the high-pressure air hose. We wound up with shiny bright carbs ready for reassembly.

    The thing is, gasoline (or the additives thereto) used to have a tendency to evolve into varnish, or something very much like it, leaving calceous deposits in tiny orifices—which sounds like an alarming medical condition. You need something that will dissolve these nacreous deposits.
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    Terry Sayther

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    You said: "The problems: dieseling, continuos smell of gas, very poor gas mileage, stalling, jittery on acceleration. Overall not an enjoyable ride. Very unpredictable.

    One thing I did notice recently is the crankcase ventilator open, no hose in there."

    Dieseling is usually caused by the idle speed being too high, and it is augmented by lean running, or retarded timing, or gasoline puddling after shut-off.

    gasoline smell is caused by gasoline vapors escaping containment, either because there is too much being dumped into the engine at the carbs, or fuel is dripping outside the carbs, or fuel is leaking elsewhere. Any of these would lead to bad mileage.

    Stalling can be due to too much fuel dumping into the carb---maybe from float levels too high or sticking floats---or vacuum leaks. Check base gaskets where carbs attach to manifold, intake gaskets where manifold attaches to head. Or as Satch suggested, some big vent hose to the intake not attached.

    The crankcase vent tube that I remember goes from the valve cover to the air filter---that one is not a vacuum leak; I'm not concerned about that one. Any hose that attaches to the intake manifold is more important. Any hose connection that has vacuum at idle must be plugged.

    My guess is that there is something amiss here that should not require serious carb work---check the basics and find the problem. Good luck, Terry
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    Satch SoSoCalifortified

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    Lionhead

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    Problem solved, and thanks everyone for helping out. After thorough cleaning of the carbs (not much junk or dirt found) a simple tool is what helped me get those dual carbs to work in harmony. A Synchrometer Tool for multiple carbs DCOE, IDF, IDA, DGV motometer dial type. This tool is almost essential to be able to put those carbs working together in top shape. I found and bought it at

    http://www.racetep.com/weberX.html#websynch

    You would have to get an adapter for your specific carb but this will help tremendously and make the job allot easier.

    For the crankcase vent opening (not related to vacuum) All I needed to do was buy a hose and a fitting that will attach to the opening of the crankcase and guide the fumes straight to the inside of both carb filters. Both carb filters have an opening in the bottom where I attached the end of each hose, solving that problem.

    About the jets I never changed them, and I am still not sure if I am using the correct ones or not... but the car is working perfectly fine now so it's time to enjoy.

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