Carb for "77" WR250 ?

Anybody know the correct carburetor for a "77" WR250? I'm looking for info on the original carburetor for this bike. I'm pretty sure it was a Bing 54, but not sure if it had a tickler button or a start lever? Any reference numbers on the carb would be of great help.
Thank You All, John

For a 77 250WR - Frame # ML16000 (and up) and the first four digits of the engine 2060 - the OEM carb is a Bing 54. Below are pics from the service and parts manual. It looks like it had both a tickler and lever.

The later Bing 54 numbers are:

54 - Carb Model
36 - Size
116 - Application # - (specific to make and model)

For the third number, give Bing Agency International (620-767-7844) a call - they are located in Kansas. They may be able to provide the third number. My lists only go up to 1976.

Yes, my frame number is above ML16000 and the engine prefix is 2060. Thank you sir, a call may be in order.

You should be able to find one fairly easy as many people switched to Mikunis. The 77 360 autos used the same bing as your 250.