reghusky

Thanks everyone for the help, I checked inside the left-hand idle hole and it looks like a small black cap has blanked it off, I suspect the mixture hole had one too, I've temporarily hot melted glue in there and it's running much better, idle is perfect now! Just gotta find carb jets base level now. Thanks again, I now have a very happy son!

That's a good idea, I was wondering what to plug the hole with! Cheers.

Yep, that's what I think Konrad, I wonder if it was meant to have a blanking plug in it which has fell out. It was running but idle was erratic. Piston, rings and crank seals have all been done.

Yes, I agree it looks like the casting is made for both. It definitely goes from outside to inside, I thought the unused side would be blocked or capped. I wondered if anyone had the 125 and could confirm or deny?

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.