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Wanting to upgrade carburetor on 1969 BMW 1600

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I have a 1969 BMW 1600, and it currently has a Weber 34 ICH carburetor (single barrel) on it. I've rebuilt the carburetor twice, and it still idles very high and won't run unless I keep the choke on. I've adjusted the fuel/air mixture, and just can't seem to get it right. I think the carb is just old. Instead of replacing it with another Weber 34 ICH, I thought this would be a good opportunity to get a performance carb instead.

I've done some research and I'm looking at replacing it with a Weber 32/36 DGV (manual choke). This is a two barrel carburetor, which means I'll have to get a new intake manifold as well.

From what I've read, I can't just use any intake manifold from a BMW 2002 because the intake holes are slightly smaller on the 1600. It sounds like there's a German company that makes a two barrel intake manifold for the 1600. It is a Cannon manifold, model 99004-095.

I'm leaning towards the DGV (manual choke) because my current carb is manual choke and I think it would require less work to make the conversion (I'm an amateur mechanic).

I'm interested if anyone has a 1600 and has upgraded to this same carburetor, or if anyone sees a potential problem with my plan.

Thanks in advance for your help.

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what head do you have? I ran the stock solex with 1600 round intake manifold on my 320i 1.8l for 10 years.

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You'll need a twin choke manifold from an e21 m10 - pretty common in Europe, and cheap. There's another thread about this recently, have a search.

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Ryan,

I had a '71 2002 many years ago and decided to try the Weber 34ICH after the throttle body of the 1 barrel solex went south; I should have replaced with another 1 barrel Solex, didn't really care for the 34ICH. If you go 2 barrel, just do the manifold swap and get a 32/36; you should be able to get the manifold from someone here on the board.

Tim

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the only thing good about that weber carb is that it fits. the rest is all sucky. even a solex with sloppy throttle plate and leaking gas all over runs better

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You'll need a twin choke manifold from an e21 m10 - pretty common in Europe, and cheap. There's another thread about this recently, have a search.

Yup, an E21 316 among other carbureted Euro E21s have 2bbl intake manifolds with the smaller ports for the 118 style head. I've got one myself.

http://realoem.com/bmw/showparts.do?model=2711&mospid=47166&btnr=11_0799&hg=11&fg=40

Being from what would be a grey market car in the US they're quite rare over here; so it's best to ask around on the British '02 Forum...

http://www.02forum.co.uk/

Though I never did lie the quality of the Cannon conversion intake, it does have the correct casting to accept the original 1bbl early style coolant hoses....

HTH

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It sounds to me like the idle jet is plugged up with a piece of dirt or debris. The same thing happened to my 2002 when it had a single 34 on it.

You can simply remove the idle jet, clean it out good, make sure you can see through it and put it back in. You should be good to go.

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34ICH weber is not jetted well for your application. All you need to do is change a few jets so your air/fuel ratios are correct-ish. You need bigger jets (its way too lean) .

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I've got an almost brand new 32/36 DGAV (water choke) that I'm trying to get rid of if you're interested. It's got less than a thousand miles on it. I bought it new last summer and about a month later decided to convert to fuel injection.

That said, I probably wouldn't have good advice on upgrading carburetors - I'm sick of em personally.

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I agree with Mike and Lorin -

save mucho money and time

Fix your present carb

remove all the jets - read any weber site for a break down drawing

showing you the location and size of jets you should have

order new jets as needed

pay close attention where any tiny rubber o-rings belong

check the float level and needle and seat condition

get this carb fixed right

it will yield good power, great fuel mileage

you'll smile

proper valve adjustment, proper point dwell angle, and timing setting FIRST!

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Thanks for all of the great advice. I've decided to give my 34ICH another try before dumping money into a new carburetor and manifold.

I found and pulled out the idle jet. It looks pretty clean, but I did notice that it is connected to a solenoid, with a wire running to the ballast resistor. After further research, it sounds like this solenoid is an idle shut off solenoid. From what I've read, it sounds like my problem could very well be a bad idle shut off solenoid. The car runs (idles high) when I have the choke on, but when I turn it off it just dies, like it's not getting any fuel.

I wasn't able to quickly locate a replacement idle shut off solenoid on the Internet. Does anyone know where I can find one. Or better yet, can I get rid of the solenoid and just use an idle jet and idle jet screw like I've seen in many of the diagrams.

Thanks again for all of your help!

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After failing to find a new fuel shut off solenoid on-line, I went into the local import parts store / Weber dealer to see if I could get one. The guy I talked to didn't have one and couldn't order one, but he suggested that I test the one on the carb and told me how to do it.

I pulled out the solenoid, unplugged the wire, turned on the ignition, grounded the body of the solenoid, and then reconnected the wire to the solenoid. When I did so, the solenoid did make a "shutting" noise, and I tested it multiple times.

I've concluded that the solenoid is indeed working, so that at least narrows it down. I got out my air compressor, and blew the heck out of the idle air jet and any other orifice I could find on the carb. I started the car, turned off the choke, and readjusted the air/fuel mixture screw and now I can at least get the car to run without the choke on. It doesn't run awesome (the idle seems to fluctuate), but it seems to be running better.

My next task is to make sure the timing is right. And then maybe make sure the jets in the carb are right for my car. Now I just have to figure out how to do those...

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