could it be a worn slide ?

[rbgaz]

hi all, on the way to southend last sat scoot started to run rough so pulled over put new plug in still the same and was getting worse as the miles went by very splutery, got to j b tuneing put it on dyno and it was by now even back fireing , so checked the sator and it was knackerd so put new one on and it was better but not right a quick look at the reed petals and we spot a damaged one prob caused by the back fireing on the dyno, so limped home at 45 as it wouldnt pull through the spluttering at all, when home ive changed the reed petals for new ones but still splutering but will pull though it in 2nd 3rd n 4th but not first, now the jetting has been the same for 3 odd years been fine, could it be a worn slide its a tmx 35 carb, when looking at the slide in the carb i can move the slide in and out 2 or 3 mm should their be this much play ?