MS 391

Soggy Bottom Outdoors · Apr 27, 2017

Just pulled the trigger on a new Stihl MS 391 with 20 inch bar. Got the gray bottle mix oil that doubled my warranty. I've ran about 3/4 tank of gas thru it so far. The bar oil adjustment screw was turned to very low or off on my pre-run once over. I turned it up run out of bar oil at the same time as gas or maybe a spoonful left. The throttle response is not the best at the trigger pull. Do you think this will get better with a few hours use or does it need a little carb adjustment. Top end, full throttle power is very good and it will pour out the chips even on KY's tough Black Jack Oak. Holler back

motownbrowne · Apr 28, 2017

Congrats on the new saw! It should loosen up considerably after a dozen tanks or so. These new strato-charged engines take longer to break in. If that doesn't do the trick, the next step is to open up the muffler a bit and retune the carb. A muffler mod will probably void your warranty though, so you might want to buy an aftermarket muffler to play with and keep your OEM one on the shelf. That way you can swap them should you need to take the saw in.

ericm979 · Apr 28, 2017

My new MS362CM loosened up quite a bit after a few tanks. Run it as is for a while.
The 362's oiler is also a bit leaner than I'd like. I've been gradually turning it up.

Soggy Bottom Outdoors · Apr 28, 2017

Right now I'm running 87 octane pump gas in the mix because that's what I had. I may try some Motomix or 93-94 octane next time. No non-alcohol gas close by. Maybe that will help with throttle response. Hoover back