aftermarket ignition coil MS261 M-tronic?

[ATH]

My MS261 C-M is behaving poorly. It will run like a dream, then just flat out quit. Sometimes it will start right back up, others it will not - not even try to fire. Usually happens after it is fully warmed up. Sometimes after a cut or two.

I couldn't get a spark last week. Wire tested good. Plug tested good. Bypassed the switch. No spark - at all. I bought an ignition coil from the dealer. It had different wire connections, so I brought it back. Fooled with the saw a little more. Cleaned some leads and the magnets. I turned the flywheel with a drill and did see a few sparks. Put everything back together and it ran great...for about 2-3 tanks of gas. Then it quit dead on me (while in the tree) yesterday. Again, I couldn't get anything. It fired right up today, but would shut off when I let up on the throttle (not sputter off...just OFF). After about 10 pulls it fired up, made a cut, then dead.

I haven't checked the spark - had to get to another appointment. If I'm not getting spark again, is it a safe bet it is the ignition module? If so, any good recommendations on an aftermarket option? $180 seems steep for a part that doesn't have a great track record. I've had the saw for 2-3 years...but I've got much older saws that don't require $180 parts. So, I'm willing to try cheap if it is out there (which I'm not finding...).

Or open to other suggestions

Thanks!

 

[DND 9000]

There is no aftermarket control unit for the C-M versions. You have to use the original one. Go to the dealer with the serial no. of the saw. With that info he can give you the right control unit that your saw needs.

 

[mountainlake]

Declining quality, higher prices. The way things are at too many company's. Steve

 

[Chainmale]

I've been able to get a spark using a drill on older saws. But had newer ones where the drill wasn't fast enough, but had spark using re-coil. Was actually a 261 I figured that out on too

 

[MartDalb]

Pictures would be nice, of carburator, micro switch, harness, solonoid, ignition module/control unit etc.

I went through hell with this one here...
https://www.arboristsite.com/threads/stihl-ms261-piston-question-burned.350813/page-8#post-7514467
Ended up getting super service via Stihl service themselves, their main department no less.

 

[oldbuzzard]

I’ve got one with the same problem - won’t run if it gets hot. Yesterday it was 90 degrees here so she shut down. I’m sure it is the ignition module. There are guys on eBay parting out brand new saws and selling the parts. You should be able to get one and save a few dollars. No one makes aftermarket coils for the CM that I know of. Be careful though as I have seen Chinese coils for straight 261s being sold as applicable for CMs.

 

[huskihl]

Don’t see many Stihl ignition coils or Mtronic units inside them go bad. I would replace the fuel solenoid. They offer a kit with a white solenoid and orange fuel filter for under $50

 

[MartDalb]

Don’t see many Stihl ignition coils or Mtronic units inside them go bad. I would replace the fuel solenoid. They offer a kit with a white solenoid and orange fuel filter for under $50

I'd still suggest reading my thread. It was defective coil, and solonoid, micro switch. Something a regular shop probably can't even fix. And I have seen, many ms261s mtronic being sold here as, wont run or can't run correctly. Something is up with the early versions, i'd wager. Mine is from 2014, early version.

Some pictures please?

 

[huskihl]

I'd still suggest reading my thread. It was defective coil, and solonoid, micro switch. Something a regular shop probably can't even fix. And I have seen, many ms261s mtronic being sold here as, wont run or can't run correctly. Something is up with the early versions, i'd wager. Mine is from 2014, early version.

Some pictures please?

I read the thread before I posted.

Mtronic coils prefer a smaller air gap and need to be turned over faster than older coils require to make good spark.

I’ve never replaced an Mtronic coil, but I’ve replaced dozens of fuel solenoids. Particularly in the 261cm. Which is why I suggested that.

 

[MartDalb]

I read the thread before I posted.

Mtronic coils prefer a smaller air gap and need to be turned over faster than older coils require to make good spark.

I’ve never replaced an Mtronic coil, but I’ve replaced dozens of fuel solenoids. Particularly in the 261cm. Which is why I suggested that.

I do not questions that, at all. And I agree on your points. Starting with the solonoid is a cheap first attempt. Solid advice.

 

[oldbuzzard]

What is the microswitch?
On the 261CM I’m having heat issues with I put another carb on it and it still had the same problem so I ruled out the solenoid - but it wasn’t new so it is possible that is still a problem. I have replaced bad solenoids before but they never had heat symptoms.
I’ll check the coil gap.

 

[ATH]

I read the thread before I posted.

Mtronic coils prefer a smaller air gap and need to be turned over faster than older coils require to make good spark.

I’ve never replaced an Mtronic coil, but I’ve replaced dozens of fuel solenoids. Particularly in the 261cm. Which is why I suggested that.

By "smaller air gap" do you mean between the coil and the wheel?

If so, maybe that is what changed when I fiddled with the saw last week. I took the coil off expecting to replace it. I cleaned everything (there was some gunk built up on the magnets). So possibly I got it back on closer than it was and cleaning the gunk off?

I'll try to get some pics today. Headed to the shop to mow a bit...

 

[huskihl]

By "smaller air gap" do you mean between the coil and the wheel?

Yes

 

[lone wolf]

I’ve got one with the same problem - won’t run if it gets hot. Yesterday it was 90 degrees here so she shut down. I’m sure it is the ignition module. There are guys on eBay parting out brand new saws and selling the parts. You should be able to get one and save a few dollars. No one makes aftermarket coils for the CM that I know of. Be careful though as I have seen Chinese coils for straight 261s being sold as applicable for CMs.

Sounds like the crap old weak gas they sell especially if it runs good when cool. Keep the can and saw in the shade when possible . You need to try some Av gas or the like first.

 

[stihltech]

You may be on the right track, but don't forget to check the fuel tank vent. Ditto on the solenoid first as there are upgrades. No Chinese parts thank goodness.

 

[oldbuzzard]

Several mentions of the “micro switch” - are you talking about the kill switch?

 

[oldbuzzard]

Sounds like the crap old weak gas they sell especially if it runs good when cool. Keep the can and saw in the shade when possible . You need to try some Av gas or the like first.

I only run Husqvarna or VP premix. Several other saws were tunning on the same gas that day with no problems.

 

[lone wolf]

My MS261 C-M is behaving poorly. It will run like a dream, then just flat out quit. Sometimes it will start right back up, others it will not - not even try to fire. Usually happens after it is fully warmed up. Sometimes after a cut or two.

I couldn't get a spark last week. Wire tested good. Plug tested good. Bypassed the switch. No spark - at all. I bought an ignition coil from the dealer. It had different wire connections, so I brought it back. Fooled with the saw a little more. Cleaned some leads and the magnets. I turned the flywheel with a drill and did see a few sparks. Put everything back together and it ran great...for about 2-3 tanks of gas. Then it quit dead on me (while in the tree) yesterday. Again, I couldn't get anything. It fired right up today, but would shut off when I let up on the throttle (not sputter off...just OFF). After about 10 pulls it fired up, made a cut, then dead.

I haven't checked the spark - had to get to another appointment. If I'm not getting spark again, is it a safe bet it is the ignition module? If so, any good recommendations on an aftermarket option? $180 seems steep for a part that doesn't have a great track record. I've had the saw for 2-3 years...but I've got much older saws that don't require $180 parts. So, I'm willing to try cheap if it is out there (which I'm not finding...).

Or open to other suggestions

Thanks!

Well when there was no spark the last time did you check with the pulstarter or drill? If you have spark with the pull starter when its hot try a new Solenoid and clean the carb out.

 

[oldbuzzard]

Don’t see many Stihl ignition coils or Mtronic units inside them go bad. I would replace the fuel solenoid. They offer a kit with a white solenoid and orange fuel filter for under $50

You are right. Fixed two 261CMs by replacing fuel solenoids. All I had were new Green solenoids. What is your opinion on the Green solenoids?

 

[huskihl]

You are right. Fixed two 261CMs by replacing fuel solenoids. All I had were new Green solenoids. What is your opinion on the Green solenoids?

Don’t have one, as I’ve never used a green solenoid. I’ve only used the white along with the orange fuel filter