carbs-diaphragms for 1980 midnight special

[s63921c]

can anyone tell me which 34 mikuni model carbs I have. I read on the forum about the diaphragms from jbm industries and want to see if they carry the right ones.the groove on my carbs appears to be 73mm,but i want to be sure if they are bs or cv carbs...thanks

[natemoen]

We have BS34 carbs. But they are cv (constant velocity) carbs. You do however need to make sure if you have the early or the late model XS carbs. Easiest way to check from the outside is to see if there is 1 or 2 T's between carb pairs (1-2 or 3-4).

[s63921c]

1980 carbs

I have 1 tee between cyl 1 and 2 carbs,and 1 tee between cyl 3 and 4 carbs. i think they are the newer style-also have no passage between the main and pilot jets.Thank you for responding!

[cywelchjr]

Unless changed from stock (which is of course always possible) all midnight specials have late style carbs.

But Nate is right, they are BS34 CV carbs, specifically BS34 MkIII carbs or they could be referred to as BS34 model III, basically the third version of the BS34 Mikuni OEM carb, which general model is still in production and use today in generally the same form as on our bikes, so I guess by the third revision Mikuni felt they had it pretty right. This of course helps keep parts available.