I just rebuilt my 38mm TM carb for my Tecate.I had to replace the internals from the stock to accomendate the mod's I did
motor ((
Internal Combustion Engine ? )) wise.
I installed a 6fj40 needle replacing the stock 6fj41
I installed a 35 slow jet from the stock 20
I installed a 389-q6 needle and seat from the stock 389-q2
I installed a 370 main from the stock 230
The throttle slide was a 4.0 I kept that.
The throttle valve was a 3.5 I kept that.
These mods made such an improvement, it seems whenever you run these carbs they need to be custom built to the specs each individual needs for there machine,Buying 1 stock direct OEM might not be correct application.