carb balancing

[manxr65]

someone sent me a plain english way of balancing carbs but i cant find it ,anyone tell me how to please , just want to confirm something i have done,.

[Lucky_Lou]

What year is it ie flat top or spring assisted.Theres allot of articles about this subject.
If you cannot use a manometer try this(best with a warmed up engine)
I have the flat tops which means fitting a manometer is near impossible so i set mine as follows...install a clean set of plugs,
Set the air screws at about 3/4 turn open as a starting point, slacken off both the throttle stops re tighten the stops with a feeler gauge about 10 thou until you make contact with the feeler then remove the feeler gauge and tighten both throttle stops about half a turn or more (adjust both the same) until you get the desired tick over 1100ish warmed up then after about 50 miles tweak the air screws after checking the plugs it works for me.If this doesn't work there may be other issues.
Lou

[manxr65]

79 dome head carbs 64/32/343. thanks

[Lucky_Lou]

The previous advice is good for any but the dome heads have a better vacuum fitting for a manometer.
Lou

[Barry]

I have the flat tops which means fitting a manometer is near impossible  

Lou, just curious why you are not able to use a manometer. My flat tops have vacuum take off points and I have the usual 5$ manometer filled with ATF which seems very sensitive and works well.

[Lucky_Lou]

I have the flat tops which means fitting a manometer is near impossible  

Lou, just curious why you are not able to use a manometer. My flat tops have vacuum take off points and I have the usual 5$ manometer filled with ATF which seems very sensitive and works well.

The take off point is a 3mm screw this is flat to the body of the carb, the later ones have this fitting mounted on a post which you can easily fit a pipe. If you know of an adaptor let me know ive tried to make one without too much success.
Lou

[montmil]

The Airhead Beemer Club is a wealth on information on the R-bikes. Check out
http://www.airheads.org/component/option,com_frontpage/Itemid,1/

Check out what the Snowbum has to say:
http://bmwmotorcycletech.info/synchcarbs.htm

Here's another good one:
http://www.airheads.org/content/view/183/98/

Monte

[Barry]

The take off point is a 3mm screw this is flat to the body of the carb

I thought the early carbs had them like mine or not a all. I can see it would be tricky to turn something to fit in a 3mm threaded hole. Anyway this is what mine look like

[montmil]

The take off point is a 3mm screw this is flat to the body of the carb

I thought the early carbs had them like mine or not a all. I can see it would be tricky to turn something to fit in a 3mm threaded hole. Anyway this is what mine look like

And if you do not have the Bing-specific, odd ball threaded 3mm screws, vinyl vacuum caps work just as well and are easier to replace when that little screw and washer disappear into some parallel universe. They are available at most well-stocked hardware stores, big box DIY businesses and auto parts emporiums.

Monte

[Lucky_Lou]

The take off point is a 3mm screw this is flat to the body of the carb

I thought the early carbs had them like mine or not a all. I can see it would be tricky to turn something to fit in a 3mm threaded hole. Anyway this is what mine look like

If you imagine that vacuum pipe fitting cut off flush with the body thats what i have.
Lou

[Lucky_Lou]

 vinyl vacuum caps work just as well
Monte[/quote]
Monte do these just stick on? im trying to imagine what they are?? that said im quite happy with the results of the "manual" method i outlined earlier.I did try to make an adapter with some spare screws from Motorworks but i failed to drill them out properly, there an odd thread not 3mm but something close.
Lou

[montmil]

Monte do these just stick on? im trying to imagine what they are?? that said im quite happy with the results of the "manual" method i outlined earlier.
Lou

Would not work on your particular carb's vacuum takeoff point, Lou.

Short vinyl or rubber closed-end tubes of various i.d. used to temporarily close off vacuum lines or ports during tuneup chores on bikes, cars, etc. The blue 'uns work great on my airheads.

Monte

[Lucky_Lou]

Thanks for clarifying that Monte, ive considered either drilling the thread and re tapping to a larger more adaptable size or gluing (Araldite or some similar compound) an adaptor but ive managed so far and i would be worried about damaging the port.
Lou

[nhmaf]

I would think maybe one might be able to find in a laboratory supply catalog or maybe a large a hardware store a brass fitting/adapter  with a 3mm threaded end and a "barb" hose end on the other end, or perhaps one could find a simple male-to-male threaded brass coupling that might serve as an adapter?

[Semper Gumby]

Hi manxR65,

I use the procedure out of the Bing Agency's Carburettor manual and a Colourtune Plug to set the idle mixtures.  Make sure your cables both throttle and choke are new and not decrepit.

As close to plane English as you can get.