* I have a 1980 BMW R100T bike.
* I had my carbs rebuilt by BING USA.
* Right now my engine is running ruff.
* I bought a ColorTune sparkplug.
* All I see through the sparkplug is a white flame no matter which way I adjust the fuel/air screw. Which I think means it's running lean. And yes I tested with the lights on and off in my garage,
* I suspect BING installed a too lean jet/s when they rebuilt my carbs.

* My question: which way should you turn the screw( in or out ) to uncrease the fuel mixture?
* I want to add more fuel to the mix but I'm not sure which way I should be turning the screw.
* I checked MaxBMW's parts Fiche and they only show (1) available jet for my carbs. Are there more?
* And how hard is it to replace the the jets with richer jets if I can find them?