MS 261 C No spark (coil?)

[Woodchiper]

As title says no spark to our 261. Mechanic took coil off and we are having a hell of a time find a replacement. Coil was taken to the Stihl dealer and they were unable to find a exact fit. The numbers on it are 1141 4703 A and lower on the coil 1514. The problem seems to be the connection for the wires.

Also, reading is there the possibility it's not the coil? Thanks.

 

[Sam R]

I wouldn't immediately assume bad coil in a no-spark situation. First thing to try is a new plug. Install it and see if you get spark. After that, check your magneto air gap, test your short circuit switch and associated wires. Make sure the boot makes a good connection & it's seated well over the coil cable. Also look at flywheel magnets, if they're blue = bad.

 

[L34]

If it is a C aka mtronic,i know on a 441c if there is a problem with the solenoid or wiring to it you can have spark problems.

 

[DND 9000]

If you need a new control unit for a MS 261 C with m-tronic use part 1141 400 4732.

 

[petarpastrakov]

I wouldn't immediately assume bad coil in a no-spark situation. First thing to try is a new plug. Install it and see if you get spark. After that, check your magneto air gap, test your short circuit switch and associated wires. Make sure the boot makes a good connection & it's seated well over the coil cable. Also look at flywheel magnets, if they're blue = bad.

Hi I have a same issue with no spark on my 261mtronik I bought few saws one of them 261 when I tried to start it it fired up once only for few seconds and that was all . tryed again replaced the spark plug I saw its going wet thold it's the carb membrane , replaced them both.tryed to start again but the same wet sparkplug then realized it's not the carb it's no spark the magneto gap is as should checked the cables don't know are they ok but they all connected as should the only thing I have to check are freewheel magnets.Im new in this things and training to find out an information about the issue.Was about to buy an ignition coil but I saw the post and I don't really know how to find out what's exactly wrong with the spark coz I'm pretty sure that it was a spark when first time tried to start the saw and wondering what whent wrong

 

[DND 9000]

As you`ve already said you should check all the wires for a proper connection. If there is a bad connection or no connection you don`t have spark or only a few seconds. Especially check the wires and connectors to the solenoid valve.

 

[user 122190]

HOW-TO Fix A Chainsaw With No Spark - Ignition Module Replacement​

 

[Wood Doctor]

If I am not mistaken, the procedure for checking for a spark shown in Post #7 fails for Mtronic engines. Once that plug is removed, the spark will not appear even if the coil is OK. Stihl wants you to use a ZAT 3 or ZAT 4 ignition system tester for the module along with a new plug.

 

[L34]

I have tried the plug out of cylinder on a 441c but DND advised me it is not the way to go.
441c had spark BTW with plug grounded to cylinder.

 

[M5Pilot]

I've been reading about bad coils for the 201T's mtronics and that new coils were no help. The solenoid gets mentioned a lot and a bad one can cause the coil not to spark. Rarely mentioned, and one I'm going to remember is the other electrical circuit in mtronic saws is a diode which tells the mtronics which position the coke is in. If either of the 2 circuits (solenoid or diode) are bad, the coil won't spark. I think Stihl has a test procedure for diode failure. Just passing on what I thought was good info.

 

[SimonHS]

Here attached are the checklists and flowcharts that Stihl use to diagnose M-tronic saws. These date from 2019. Hope they are useful.