A good source to end the debate..go to your local motor cycle shop and ask to speak to someone up with the play on MX 2 strokes..don't be surprized to hear the top riders replace their rings (only) each meeting or so to keep the cylinder "fresh". You can't hone the "jugs" unless they are from an old saw with iron or steel cylinder inserts. modern saws from about the early 70s on have been using either chrome or Nikasil electro plated coating direct on the ali block casting for 2 reasons..being hard material, it lasts longer within defined tollerances..more importantly there is netter heat transfer from the piston - through the rings - to the cooling cylinder block. When the cylinder bore starts to score/scratch the contact between the cylinder and the rings diminishes and the rings (& piston) run hotter, leading to further wear and scoring..2 strokes unlike 4 strokes, have their rings pinned so they can't rotate around the piston (because thre ring end could pop into a port and jam/seize), by replacing the rings while the bore is still clean (score free)..because the rings are pinned, they tend to wear differently adjacent to respective ports and go out of round..new rings (for all 2 strokes these days) are finely ground (round)..by keeping you saws rings fresh..they will tend to wear your bore "round" and help it last a whole lot longer. Go speak to the local hot motorX 2 stroke mechanic and make up your own mind...
To check if the rings are sagging and losing tention, add a squirt of oil down the plug hole after test the compression, and compare the 2 readings (there shouldn't be more than 10psi difference with good rings)..
If you do, do a ring replacement..get someone to tickle up the porting a little..don't change the port shapes or size (especially at the cylinder wall, just smooth out the casting and match the cylinder port passage, to the crank case passage unless you really know what you are doing...you'll be amazed at the difference
