MS 311

Dennis W · Monday at 3:03 PM

I've had my 311 for 3-4 years. It's always been hard to start. Get to a job and won't start or starts then won't restart after shut down. It's not my main saw, so it's not used every day/month. Good thing I can rely on my old 028 to save my butt.
Last year I couldn't get it started after working on it. Took it in for repair and it started a couple of time, then back to 'will it start or not'. Having the same problem now... replaced the spark plug and coil and got it to start after pulling my ass off with the switch in ' off ', 'run', and 'choke'. Seems to flood easily.
Every video I watch, they start easily. I never had a Stihl be this much of a problem

Questions ?? What seems to be the problem with this saw? Is the Carb bad? When looking up parts the diagram pic looks different then mine.
Will the carb from my old 291 work on this saw?

Bob Hedgecutter · Monday at 6:50 PM

Ah the big Stihl plastic saws- gotta love to hate them.

First thing I would be doing is checking the condition of the piston through the exhaust port with the muffler off.
Next thing would be pressure testing the fuel line with the filter removed- thus also testing the carb.
Plastic clamshell design- known to leak at some stage of life- check the four bolts that hole the clammy cylinder to the plastic case.

Find a better repair shop- sounds like the one you used does not know excrement from clay.

Dennis W · 2025-09-10T09:16:19-0400

Thanks for your reply. Some of your suggestions are beyond my ability, and I've been trying to locate a 'Stilh" technician. After years of local business our local Stihl dealer retired. There's a couple more dealers in the area, but not sure about their repair abilities beyond spark plugs and card cleaning.
In your reply, you mentioned 'Clammy cylinder'. A term I'm unfamiliar with. I could check those four bolts if I knew where they are.

Bob Hedgecutter · 2025-09-10T13:52:19-0400

Dennis W said:
Thanks for your reply. Some of your suggestions are beyond my ability, and I've been trying to locate a 'Stilh" technician. After years of local business our local Stihl dealer retired. There's a couple more dealers in the area, but not sure about their repair abilities beyond spark plugs and card cleaning.
In your reply, you mentioned 'Clammy cylinder'. A term I'm unfamiliar with. I could check those four bolts if I knew where they are.

Clammy cylinder = clamshell design- where the machine has a plastic case and the cylinder extends down to form half of the crank encapsulating area- like a clamshell.
Under the saw, bottom of the case, partially hidden under the tank tail- are four T27 bolts that hold the cylinder to the plastic half of the crankcase, if these are loose- air will be sucked into the system, sealant between the two shell halves are likely compromised and so too the main oil seals.
Leads to lean conditions and hard starting.
Take the muffler off and provide photos of the piston as viewed through the exhaust port of the cylinder- that will answer a lot of questions.

MS 311

Dennis W

New member

Bob Hedgecutter

Moderator

Dennis W

New member

Bob Hedgecutter

Moderator