38mm Bing Needle Size

[Bill Campbell]

Can anyone out there let me know the dimensions for a needle that will fit a 38 mm Bing. I am running a 3.22 needle jet and I have a needle with four rings on it. It has a diameter of 2.97 mm. Can I get a larger needle as my 76 400 is running rich when I close the throttle. If I need a larger needle will it have a part number and where could I get one from?

[El-Viejo]

Try this:
http://bingcarburetor.com/

They have anything I have ever needed for my Beemers.  Never tried to get anything for the KTM yet.

[farmer58za]

Hi Bill
I don't know about the needle  but I have # 320, 318 and 310 needle jets if you can't get them down under. Is the needle jet the one with the body of 9.7mm diameter?

The needle jet size will affect the running at 1/8 - 3/8  throttle

David in SA

Ps. My '75 400 has stock jetting of a 2.83 needle jet but the needle is of the order of 2.6mm diameter

[farmer58za]

Hi Bill
Sorry, I forgot to ask: Is the carb the original stock item? If so, then the needle and needle jet will almost certainly be worn and will need replacing. No kidding, the needle jet on mine was worn oval!

David

[Bill Campbell]

David thanks for the the response. Without checking it I think your specs are for an earlier version carb. My 74 250 runs needle jets and needles like that and it has an older model Bing. My carby did not come with the bike and I have tried to set it up as per stock specs but it is difficult to ascertain what is the correct needle for the needle jet.  Bill

[farmer58za]

Bill
I can't help you on the needle. Bing carb parts are almost unobtainable here. I needed a # 2.83 needle jet so to get the bike running better in the short term I just turned up a new jet out of a pin from 15A plug and drilled it with a 2.8mm drill. The last .03mm was a hit or miss affair with grinding paste!

Bike is now running magic.

Try Helmut Clasen who posts on this board as "Speedy" he's a great help with years of knowledge.

regards
David