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'77-'79 XS400 Twins with Mikuni Second Gen Early Style BS34 Carbs

This is the first gen XS400 carbs which are second gen early style BS34 Mikuni carbs. This was the first version of the BS34 that mounted the jets to the body instead of to the float bowl itself. However, these carbs used a smaller diaphragm than the later style BS34. These carbs require a special cleaning process or they come out horrible. They are also easy to mix-up due to the ID number being acid etched into the upper bell housing and hard, if not impossible, to read. 

Note: Starting in '74 Yamaha started year coding bikes in the last letter used in the name. You may see this code on your bikes paperwork or in a parts list or catalog.  I leave this off as it is redundant if you are showing the year anyway. There is a chart below to find your year code.

I do not have any pictures of these particular sets as they are almost never used on the 400's due to being very easy to get destroyed from sitting. I hope to have some to show soon, but since they used these motors for Micro Midget racing for years, they are rare to find.

'77 XS400-----------------------------------------2A2
'78-'79 XS400------------------------------------2L0
'78 XS400-2--------------------------------------2G5
'79 XS400-2--------------------------------------2L0