On 12/27/2015 11:32 AM, Michael wrote:
I added premium unleaded to my gas can (plus oil) this time around for my chainsaw. My chainsaw seemed to run a little hotter, which was helpful, but I wonder if this is not the best thing for the machine. Any thoughts? Thanks.

Should not matter at all, Premium over regular is simply more of an
additive to increase octane to help prevent engine knock.

Vehicles have knock sensors that listen for knock and will retard the
ignition timing to help prevent engine knock with cheaper grades of
fuel. Premium fuel typically helps to prevent knock and the ignition
timing will electronically advance for better power and gas mileage.

In the old days when you set the ignition timing manually the engines
would truly run hotter if you advanced the timing too much.

Relatively modern engines these days monitor all of the engine functions
and make adjustments accordingly.

If you chain saw has an electronic ignition and a knock sensor the
timing could be advancing with premium fuel and running hotter. Or you
could simply be getting a more complete burn with the better fuel and
naturally running a bit hotter.