Had one come in this morning. "want start" on the ticket.
Turns out it did not have any fire. A little rare actually.
So, I put a new ignition module on it . Still no fire. Disconnected the kill wire. Still no fire.
Guess what. There are two different ignitions for those saws.
One for the rectangle air filter vintage. Another for the round air filter.
Now, I would have thought it would fire some time even if wrong time . But, no.
So, I put the correct module on and off she went. I thought Stihl had quit doing that stuff.
Oh well. 11404001303 for the rectangle. 11404001307 for the round .
BTW, those white sheets of paper on those boxes that you throw away. Sometimes it is good to read them.
New Member here. This series on ms311 spark issues helped me so sharing my repair experience. Maybe help others. Agree with prior post(s)... something weird or intermittent function on Stihl OE ms311/ms391 ignition coils.
See attached Coil ID Marking for "C" or "D" version. Can only verify the OE 1140 400 1303 came as "D" marking... made in Germany.
Installed new/nla OE Coil 1140 400 1303 to fix issue. If issue repeats I'll try to post an update. {Keeping old coil for 'next time'}
Yes, white paper inside new OE 1140 400 1303 box confirms previous mention. For ms311 & ms391.
-- square nylon mesh air filter (rev.01), use coil# 1140 400 1303
-- round pleated air filter (rev.02), use coil# 1140 400 1307
These other AS posts frame the same issue. Each consistent to my experience.
"Stihl MS 311 Won't Start", DECJ, Sep 28, 2011
"MS311 No Spark", BIG JAKE, Nov 26, 2012
"MS391 - not running, likely no spark - Help", ppsathas, Mar 24, 2020. [The markings on the original coil are: 1140 1301 C, MC 1140F, MS 1140, MJ 171]
My neighbor brought over a new to them Stihl ms311. Condition obvious that very few hours & they ran 4 tanks of continuous cutting without a problem. Then a few days later can't start.
Quick check it has no spark so he leaves with me to investigate. Do as everyone else; new plug, bypass Ignition kill wire, gap coil, check magnets, clean coil & ground, remove plug boot to ensure proper spring terminal fitment, secondary measures at 2k ohms, no spark.
I'm aware that following procedure is not reliable troubleshooting. Many coils require the instantaneous rotational speed of a recoil strong & swift pull.
Removed plug so spins freely without compression (ensure Ignition ON), hold plug firmly grounded to jug, carefully spin flywheel by a drill motor & socket bit (CCW). No spark.
Repeat & sustain drill motor at max speed. Plug starts arcing. Changing speeds up/down continues arcing. Seemingly behaved as if spinning flywheel restores magnetism field or provokes a coil electronics reset. Don't know, just this unit resumed spark generation. Another user mentions; 'those ms311 are slow to generate spark'. As if discovered something similar... pull, pull, pull, eventually get spark back. But, no guarantees here.
Reassembly recoil, pull, no spark. So set aside while putting carb kit into another saw. Before leaving shop I yank on the ms311 again, just because don't get it... dang if it Pops & then STARTS. Runs fine. Stop & Restarts okay. Next morning still restarts on 2 pulls. Wow, very confusing.
Customer accepted to install new OE Coil. Got extremely lucky here, @Nov'24 our local John Deere chain had correct IPL coil in stock at another location. Free store to store transfer. So ordered new OE (yes, nla) 1140 400 1303. Arrived as PRUfTEX manufactured coil, marking "1140 1301 D".
Intermittent function coil (maybe or maybe not Original ms311)
... Unknown Stihl PN
... 1140 1301 C, MC 1140F, MS 1140 [NG 043]
>> Secondary: 2127 ohms
>> Primary: implausible to measure
New OE 1140 400 1303
... Stihl / IPI 2000 PRUfTEX
... 1140 1301 D, MC 1140F,
MS 1140 [XF282], Made in Germany.
>> Secondary: 2050 ohms
>> Primary: implausible, sinking or charging IC, initially 4 mega-ohms drifts to 2 mega-ohms. Keeps drifting. No useful value.
Removed Bosch WSR6F measured 10k ohms.
New installed NGK BPMR7A measures 8.3k ohms.
Not certain here but ms311/ms391 coil version "1140 1301 C" seems to have given problems. Both my experience & stated AS member, ppsathas, Mar 24 2020.
I cannot endorse whether exists a suitable aftermarket coil for Stihl 1140 400 1303.
Searches reveal description 1140 400 1303 / 1140 400 1307 universal fitment. This is not correct to Stihl OE instructions. Not shared coil / interchange, but 1140 400 1303 is now NLA.
