You might could check the turns out of idle screws, then remove and shoot some carb spray in each. But what I’d do at minimum is leave the carb on, measure what clearance I have on front/rear pump arms, pull the bowls and blocks then do the carb spray and compressed air deal to all the orifices, air bleeds etc in the idle circuit. Reassemble and check/reset the pump arms clearance and set idle screws to what they were and see what happens go from there. Might solve it, might be something else. :)