MS201TC slow to pick up

[TayloredTrees]

G’day fellas, been trying to find or work out an answer to a annoying problem with 201TC. I’ve mildly ported it, really only working upper transfers, just opening them up a bit, and widening n polishing exhaust with standard muffler mod. It’s improved the performance quiet a bit but it’s sometimes slow to pick up, the ‘crack’ I think some people call it isn’t always ‘zippy’. It’s seems to correct it’s self if I reset carb, let it idle on half choke etc. so leads me to think it’s a carb problem. I’ve 2 carbs, one hogged out and one factory and both after a few cuts seem to lack this ‘crack’. The saw however will pick up even if I’ve started a cut but it’s that second before which is very annoying when your after a zippy saw. Has anyone experienced similar problems?
Thanks from Australia!