Jonsered cs2255 carb adjust limiter?

[AndyVT]

After years of using this saw I just took it for granted that it was just a slow revving saw...until now!
I tried turning the screws in and only could move them slightly more than 1/2 turn.
I googled "carb adjust limiter removal" and the examples showed an obvious plastic retainer that has to come out or at least trimmed
On this saw the screws fill the whole port with no noticeable plastic piece .
Anyone familiar with this?