Mikuni 20 mm carb mystery part

[Murphy PNW]

Happy Christmas everyone.

I have what hopefully is not a stupid question. I ordered a rebuild kit for the 20 mm Mikuni carburetor. It came with a number of obvious parts, but also one that I have been unable to identify. It is a black plastic cap thingy, approximately 10 mm across. Does anyone know what this is? So far I can't figure out why it was included in the kit. There is no such part on the existing carburetor or on the parts list.

I am also in searching for a chain guard for a model 90/92 (any condition) and a side stand long enough to fit a model 96 Dirt Squirt.

If you happen to have either part, please let me know. I can be reached at 206 nine-five-four 9925.

Thanks all. James

[Bullfrog]

Does it fit up to the starter circuit plunger? (choke) I think there is a compliant seal in there.
Ed

[Murphy PNW]

Thanks Ed for the response. Good point. I thought that, but this is a cap and doesn't have a hole in the center.

This cap was included in the kit from HodakaParts.com, and I have bought several of these kits. Each one comes with this cap thingy.

I have not tried to drill a hole in it. If that is what was intended, it certainly was not clear.

The standard rebuild kit comes with a reprinted version of chapter XI, pages 99 through 108, of the Ace 90 Workshop Manual (1967). I am also referencing, while performing the rebuild, the exploded diagram of the carburetor on page 110 of the Manual. Item 29 is described as the "starter plunger unit." At page 106, paragraph 3), the Manual describes pulling off the rubber cap, prying free the retainer clip from the brass plunger holder, and separating the components . I have not pried off the black seal because the kit does not include a replacement neoprene seal. The old one looked good enough for my purposes. I didn't see a need to replace the cap on the plunger of the choke / starter device in any event.

I have saved the caps in case anyone else knows the intended purpose of this item. Regards, James

[viclioce]

Not a clear photo, but, could it be the top cap to the choke plunger? See the attached picture. It fits on top of the plunger #32. Just a guess. Hard to tell from pic. Victor