I’d just seal it up with a sheet of 3mm plastic. Avoid using through bolts if you can. You don’t want hardware going through the engine.
The hyosung doesn’t like pod filters, many of us worldwide have tried to use pods but the bike becomes unstable and its a very frustrating war of messing with the carbs everyday. Trust me, the airbox wins. As Jim said above ^ , why not a metal/plastic sheet there and use “JB WELD EPOXY HIGH TEMP” for plastic. This could be the cheapest and easiest solution. No screws. Otherwise it may rattle and end up inside the engine and it explodes , very good advise from Jim
Ok, I have glued the hole with a plastic sheet and glue that says it can withstand 100ºC.
But it still goes bad. I have recorded a video, the motorcycle starts cold without the need for the choke. I also noticed that the AIS hose was not attached to the airbox but is attached to the exhaust. Plus it does a lot of “pop pop pop pop”. The intake nozzles are cracked.
Well, in the video it looks like the bike is going well, until at one point it seems to die but it recovers and finally dies suddenly.
At minute 0:30 and 1:18.
I suspect that the previous owner has messed up with the screws of the pilot jets.
At the moment I have ordered a gasket kit to clean the carburettor.
Regarding the intake nozzles, do I cover them in silicone?
Oh, by the way, putting the airbox in has been a pain. Any advice for next time?
Thanks again.