The collars get brittle with age, then the tabs will break off. If you are lucky they will hang a carb open, set off the TORS (if it isn't bypassed and you will find the problem. If you aren't lucky and one breaks on a WOT run it can/will get ingested into the crankcase destroying parts in the process. Broken piston, bent rod, junked cylinder, head crankcase.
Potentially catastrophic. I bought one that broke a piston bad enough that the rod shoved a big piece of it back through the reed cage, bent the rod, broke out the bottom of the case and still ran. The guy limped in home on 3 but ended up wreaking the adjoining cylinder because it was ingesting debris thrown into the airbox from the fist one's coming apart.
Break the tabs off, leave the white tube/collar in. The airbox boot's clamp will hold the collar in and it will run fine.
opsled