Changed air filter, M-Tronic not having it

[newforest]

Saw has been running fine the last couple days but air filter was far more brown than new looking so I changed it out.

Saw started fine but was instantly obviously unhappy and quit completely within a minute or so. Was hard to re-start and then died even quicker the second time.

Saw was 100% cold from sitting in truck bed on a 30 degree low overnight. So to make things worse I guess I changed the shroud to the winter setting as I will be running in 30-ish degree weather for quite a while. Now saw won’t start at all.

Will probably change the shroud back right now and currently warming the saw up with the truck footwell and will see what happens.

In a general sense, did I miss some procedural step to changing the air filter on an M-tronic saw?

 

[newforest]

Well that was simple enough, I think. It appears M-Tronic may not have been nimble enough to adjust to its suddenly new and improved airflow and it sent in enough fuel to push the spark plug one sheen of oil over the line. Wire brushing the plug didn’t get r done neither. The plug wasn’t as black as they usually are when they are all the way kaput, but it appears the trick I needed was to change the plug @ same time as air filter. Even running this thing (FS 560) with no spark arrestor it burns up plugs faster than any motor I have ever seen. I have long suspected that the +/- on the manufacturing tolerance of the fuel nozzle diameter went all the way to the plus side but M-tronic can only presume that nozzle is the perfect as-designed diameter.

For anyone reading the plugs@StihlDealer thread, yup, it was a high priced Brazil NGK plug, after I complained about them selling expensive but junk Champion plugs. I will look into just buying them from the automobile supply chain I think; though I like to support my dealers a 20 minute drive each way ain’t worth it to give them a couple bucks for cheap junk anyway.

Though also I doubt a true from-the-stash German/Japan plug would make much difference in a saw that simply runs a tad too rich and nothing can be done about it. When I finish reading that plug thread maybe I too will hope to meet a guy who knows a guy who I can ask - yo gotta any more of that green Bosch, bro?

 

[WI_Hedgehog]

If I recall, M-Tronic stores the last settings and uses them at the next startup, then tunes for the current conditions. To me it sounds like conditions changed too much for the system to compensate for.

 

[dmb2613]

Just reset the M Tronic , start it on choke and let it run for 90 sec on choke then rev it up should reset everything

 

[newforest]

That’s the kind of needed process step I was hoping to discover, thanks!

I planned to start it and let it idle extra long for the most part so M-Tronic could figure out air flow was better than the day before. But I have a habit of hitting the throttle to knock down the ‘high idle’ after starting and on this saw, that closes the choke automatically.

So I let it idle low for over a minute then tried to give it RPMs. Died. Did same thing again, died idling. Then experimentally flipped the air shroud, wouldn’t start. Plug was gone by then anyway.

Saw running perfect again now.

 

[Del_]

Just yesterday my 241C-M acted up. It had not been run in a few weeks and the outside temperature was about 45°F and the last time it was run it was about 75°F. The 241C started then stalled out on the first small 3" cut. I started it up again and it ran a little funny but I continued making small limbing cuts and it was running fine in a couple of minutes. Ran fine for another couple of hours until I was finished. Love that saw!

I've read about the high idle for 90 seconds and tried it a few months ago just for fun.

I've also read about making 5 or 6 small cuts in a row going to idle between cuts.

I'm wonder which is the suggested method for my 241C-M?

Or if either method works just fine.

 

[huskihl]

Just yesterday my 241C-M acted up. It had not been run in a few weeks and the outside temperature was about 45°F and the last time it was run it was about 75°F. The 241C started then stalled out on the first small 3" cut. I started it up again and it ran a little funny but I continued making small limbing cuts and it was running fine in a couple of minutes. Ran fine for another couple of hours until I was finished. Love that saw!

I've read about the high idle for 90 seconds and tried it a few months ago just for fun.

I've also read about making 5 or 6 small cuts in a row going to idle between cuts.

I'm wonder which is the suggested method for my 241C-M?

Or if either method works just fine.

Run for 60 seconds in the choke position. Without touching throttle, move switch to off. Move switch back to on and let idle for 60 seconds. Make at least 5 consecutive long cuts. That resets the v1 and v2 mtronic

 

[Del_]

Run for 60 seconds in the choke position. Without touching throttle, move switch to off. Move switch back to on and let idle for 60 seconds. Make at least 5 consecutive long cuts. That resets the v1 and v2 mtronic

Thanks so much.

Do you think it reset after my running if for an hour or so?

It seems it did.

I've had my 241C for about a six months and have very little time on it.

Would mine be a V1, or a V2 mtronic?

 

[huskihl]

Thanks so much.

Do you think it reset after my running if for an hour or so?

It seems it did.

I've had my 241C for about a six months and have very little time on it.

Would mine be a V1, or a V2 mtronic?

I believe so. On this early procedure, (like your 241) it’s just a reset. Returns the settings to ground zero.

The latest version 3 mtron uses a calibration procedure that it different from this reset procedure. Only some of the newer saws use v3.

 

[Doorfx]

Run for 60 seconds in the choke position. Without touching throttle, move switch to off. Move switch back to on and let idle for 60 seconds. Make at least 5 consecutive long cuts. That resets the v1 and v2 mtronic

When you say “ move switch to off. Move switch back to on”
Do you mean flip it quickly so it doesn’t shut off or do you mean shut it off and restart it ?

 

[huskihl]

When you say “ move switch to off. Move switch back to on”
Do you mean flip it quickly so it doesn’t shut off or do you mean shut it off and restart it ?

Shut it off. Move switch to run. Restart.

Don’t touch the trigger during the reset procedure

 

[Doorfx]

Shut it off. Move switch to run. Restart.

Don’t touch the trigger during the reset procedure

Thanks

 

[drf255]

To the OP, the mix you use can make a difference in these saws. I learned that the hard way, when I was using Motul800 at 30:1. Ice cold mix into a warm saw was too viscous to flow correctly and messed up the MT. A switch in mix and all was well for me.

 

[newforest]

I stick with no-Ethanol 50:1 HP Ultra exclusively (even in those other Orange&Black saws). Any time a saw will be put away for a few weeks or a few months due to other work, I run some MotoMix or XP pre-mix through it first though my reason for that is mainly for the stabilizers to keep the fuel lines, etc. a little happier in storage. I always keep a can of that with me anyway for when I am not running a saw all day but might discover a tree in the road, etc.

The one time I tried any other mix in M-Tronic didn’t go well at all. I believe it was a can of 40:1 pre-mix I purchased when blizzardy roads nixed any other option. Plug fouled right away and so did a second, new one though after 15 minutes instead of 3.


This has been a handy thread though, thanks everyone. Have been mowing down so much 1-2” White Pine every day I smell like a Christmas Tree and my customer is probably increasing the future value of their block by a factor of 5, maybe 10. “We had no idea there was so much Red Pine out there.”