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Main Jet Holder


Question. On a 1971 R75/5 (12/70) with early Bing carbs does the main jet holder take a o-ring like the later versions?IMG_0943.jpeg
Gentlemen, there certainly is an o-ring required: Item #11, in the above exploded view from the BING AGENCY manual.

The Main Jet (#1), Washer (#12), Jet Stock (#10), O-ring (#11), are all fully immersed to the bottom of the Float Bowl. The O-ring prevents fuel migration to bypass the Main Jet; up the threads past the Jet Stock; around the Needle Jet and into the Atomizer chamber; enriching the metered fuel.

In the following pictures, you can see that the Jet Stock, Idle Jet and Idle Mixture Screw locations, all have counter-bores following threading to enable a smooth bore for the O-rings; the Jet Stock with annulus for the O-ring; BINGS’ #1 Overhaul Gasket Kit CV with, among other items, the O-ring quantity and locations.

Hope this helps…