Wally world gas station here is all ethanol gas. I have to drive 25+ miles one way to a place to get it and they have a dedicated pump for 91 e-free gas.

Yeah the CS-400 is a bit small for the 18" bar, I think it should only have a 16" max bar. I see that it comes with an 18" bar but........ Is that a Low Profile chain? If so, that's why, 40cc isn't a lot of grunt to pull it through a tree. My CS-340 is a 33.4cc saw and it has a low profile chain on it. A 16" bar will drag it down, 14" is a LOT better. Lots of guys run them with a 12" bar.

My middle saw is a 50cc saw and I have an 18" chain on it. No issues with that. The big saw is a 79 cc, 6.3 hp saw and if the chain is sharp I can't slow down the 24" bar/chain.

The chain should be throwing chips, if you see sawdust, then it's dull.

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