I got a new to me ms170 (Stihl MS 170 14" Chainsaw for parts not working - eBay (item 280712201791 end time Jul-26-11 15:51:45 PDT)) was told it was low on comression. When the ups guy drops it off today i tear open the box to see what awaits me. Its kinda dirty but not beat to death yet, the muffler is losse like it was removed to look at the piston. Finger tight so take a look at the piston not a scuff to be seen but lots of carbon about 20% of the exhaust port is closed off. I clean off the piston and the exhaust port with some seafoam and carb cleaner give the whole saw a good cleaning . So at this point im kinda confused. so i do a compression test and get 103# cold with about 6 pulls and the fast idle set. Is 103# enough? My comp tester is a mac pro one with every adapter and hose only used about 25 times. I cant get this thing to run or even sputter. The plug is getting wet after about 10 pulls and its got great blue spark. I guess it time for rings. Whats AS have to say?