Hello, I wonder if anyone can help please? My son has a rev 3 125 2006 with the dellorto VHST 26 carb. I have taken the carb out to clean it and check jets, it has a threaded hole here which leads straight into the carb bore, should this be blanked off? I can't believe it's right to let unfiltered air straight into the engine?! Also does anyone know the standard jets/needle position for the dellorto? Thank you.
