I have 40 acres of oak forest, and heat with an outdoor wood furnace...generally, I cut about 8 cords of wood each year to feed the furnace. I have a 15 yr. old Stihl 036 Pro that I have used all these years, and last Fall it blew a crankshaft bearing. Since I needed to get busy on the firewood, I went to the store and bought a new MS391. It works great, but is a real trick to start after sitting for several days/weeks. There seems to be a real fine line between starting and flooding the engine. I have tried several variations of choking, etc., and if I'm not real careful, I will flood the engine. Does anyone else have a MS391, and have any tips on starting one of these? During the winter, I tore the old 036 down, and rebuilt it, so now I have 2 great chainsaws...if I can just figure out a technique to start this 391 more easily. Once its warmed up, it fires right up on the first or second pull....it is just the cold start that is an aggravation.
Stihl MS391 hard to start
- Thread starter deminin
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The trick I have used on various Stihl saws is crank until you hear the little pfft of start, and then take it off choke and continue cranking until it starts. No more than 4 pulls with the choke on. The older saws would run a couple of seconds with the choke on, but the new ones just slightly fire, and if you miss it, it will flood on the next pull.
Yeah, I suspect the problem is more ME than the saw. My 036 Pro fires right up on the 3rd or 4th pull with the choke, then settles down to a good run as soon as I release the choke. This new 391 has two choke settings..."cold" and "warm", and is really a bit tricky to get the first "cough" without flooding. Plus, these newer saws have more ""EPA" regulations imposed, so that also makes them a bit touchy. I've got a couple of big oak trees in the yard that didn't survive the Winter, so when the Spring yard work settles down a bit, I'm going to get in some more "practice" with the new saw, and get it figured out before I start the serious Fall firewood cutting.
Nwatson99
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The MS391 has the piston decompression on it.
Push the button to decompress the piston pressure
Squeeze the trigger move it down to choke
two good pulls it will hit
flip up to run, pull it and you should be running like a demon.
The 391 is one heck of a good saw and it will cut the heck out of the wood never thinking twice about it.
Push the button to decompress the piston pressure
Squeeze the trigger move it down to choke
two good pulls it will hit
flip up to run, pull it and you should be running like a demon.
The 391 is one heck of a good saw and it will cut the heck out of the wood never thinking twice about it.
Yup, the MS 391 has a decompression valve....just like my 036 Pro. The thing that is unique about the MS391 is that its carburetor has two butterfly valves...one for the choke, and the other for the run. It also has two choke settings, which feed different amounts of fuel during choke. I have found that after sitting for a few weeks, two pulls on "cold" choke, then switching to "warm" choke, for two pulls usually results in a "burp". Then, if I'm lucky, it will catch and start to run if I give it full throttle. Once it runs for a few seconds, all is well, and I can cut for hours with no trouble. It is very touchy though, and if this routine doesn't work, it will flood, then I almost have to pull the plug and clear the cylinder before I can repeat the process. I have found other people who have had the same issue, but they say that once it gets 20 or 30 hours of run time, and breaks in good, it generally starts much better. Once its ready to run, it will cut through anything, including a 70 ft oak tree...just like my old 036. When I bought this 391, I was seriously considering an 441 or 461, but I'm getting too old to handle that much saw.