Stihl MS441CRM-Tronic Ported Work Saw Review

[deye223]

Having cut Stringybark plenty, I know it's traits. A saw can sound like it's a little low on torque in this stuff when in actual fact it's the fibrous bark slowing the saw. It clogs up the bar and chain etc. On occasions I've had to remove the bar and chain as it was the only way I could get the chain to move. A common habit of mine is to rev the saw out of the wood to clear things out.

It's running well there Andrew.

:msp_thumbup:

i hear you on that one even worse with a 25" b&c

 

[Stihlman441]

I was thinking about what Matt said there awhile ago about the muff surface being to hot on a 441 to pass some regs in South Ozz when he was doing the felling coarses.So i had a play and made some cuts and tryed to measure the temp as soon as i could and the highest i got was 160 deg C, idearly you need someone there to take the reading in the cut.

 

[Stihlman441]

Cant work this Works Connection tach problem out,it ok at idle but up in the rev range it reads double,i put my Tech Tach around the spark plug lead and the same thing happens ?.There is three setting on the tach but still no go.:censored:
Here is a pic the way i have it set up the same as i have dont with other saws,the 261 works all good.

The fly wheel has two points to transfer signal from for the coil and two places on the fly wheel.

I allso noticed under the cover where normally you adjust carb settings there is a plug in connection,this is for the Stihl Tec to plug in and check for folts ect,there is a fine plastic wire type peace will tails on the ends covering the plug in point,so you would have to cut this off before plugging in connection.

 

[MCW]

I was thinking about what Matt said there awhile ago about the muff surface being to hot on a 441 to pass some regs in South Ozz when he was doing the felling coarses.So i had a play and made some cuts and tryed to measure the temp as soon as i could and the highest i got was 160 deg C, idearly you need someone there to take the reading in the cut.

I can't remember the exact test procedure mate but would suspect a modified muffler like yours would run cooler. The guy running this felling course also thought a gutted muffler would produce a lower reading as well.

At least the hour metre works old son

 

[deye223]

Can work this Works Connection tach problem out,it ok at idle but up in the rev range it reads double,i put my Tech Tach around the spark plug lead and the same thing happens ?.There is three setting on the tach but still no go.:censored:
Here is a pic the way i have it set up the same as i have dont with other saws,the 261 works all good.

The fly wheel has two points to transfer signal from for the coil and two places on the fly wheel.

I allso noticed under the cover where normally you adjust carb settings there is a plug in connection,this is for the Stihl Tec to plug in and check for folts ect,there is a fine plastic wire type peace will tails on the ends covering the plug in point,so you would have to cut this off before plugging in connection.

just a stab in the dark andrew have you tryed wraping the wire around the lead 8 or 9 times??
maybe 5 not enough for this system

 

[Stihlman441]

The thing is i put my Tec Tach clamp around the spark plug wire and same sh_t no good as well.:msp_thumbdn:

 

[deye223]

The thing is i put my Tec Tach clamp around the spark plug wire and same sh_t no good as well.:msp_thumbdn:

only other thing i could think of was the EFI seting but you tryed that????

 

[Officer's Match]

Wonder if the M-Tronic system reads rpms in half-rpm, ie 2 per revolution. That way it would be twice as fast at adjusting the mixture, actually measuring accel/decel within the revolution? Anybody tached a 576AT?

 

[Stihlman441]

Good point, but there would not be twice as many signals going up the spark plug wire ?.

 

[David (saltas)]

Andrew my educated guess (electritian,instrument fitter diploma electrical and electronic engineering)

Having an ellectronic controller for the fuel ( rich / lean ) and also likely ignition ( advance / retard) in such close proximity the coil and coil wire is a electrically nosey environment and one that would be prone to interference.

I strongly suspect the coil and coil wire have been shielded (Faraday cage).

The both tacho's maybe picking up some weak leakage at idle.

The tacho's maybe picking up a weak shielded signal and the grounding of the signal (also weak) and doubling the reading.

I think I remember reading some info about the wires to attach the stihl read out tool Anicol will remember better than me.

the two wires are likely to be 0~5VDC pulse train that has all of the information encoded in it.

 

[Officer's Match]

Good point, but there would not be twice as many signals going up the spark plug wire ?.

[slaps forehead] Uh, yup. :redface: That is weird.

 

[Stihlman441]

So is there a way i can sheild the wire coming from the tach to stop the unwonted signals ?.

 

[Slamm]

I just remembered the MSD ignition systems ......... Multi Spark Discharge. You had to get an adaptor or something:
(Some reading about the MSD system)
In the real world, this how an MSD Ignition works. At low rpm the MSD produces a series of sparks during each firing instead of one like a conventional ignition. At low engine speeds when the air/fuel molecules are not finely atomized, the multiple spark feature still ignites the mixture. But this isn't the only feature. The number of sparks produced by the MSD Is reduced as engine rpm increases simply because "time" becomes too short to repeat a spark. However, the spark series always lasts for 20 degrees of crankshaft rotation no matter what the rpm and no matter whether it is a single spark or a series of four or five spark. This 20 degree duration spark sequence insures that the air/fuel mixture is ignited and completely burned. Also each spark the MSD produces is an extremely high current spark. Current is like the heat of the flamethrower. Current is what actually does the work or in this case ignites the fuel mixture. Together, the multiple sparks, the high current and the 20 degree duration, produce an ignition that is superior to any other ignition. More importantly though, the MSD Ignition ignites the fuel mixture in the cylinder instantly and insure complete combustion, no matter what the molecular composition is. The result is reduced variations in burn times and therefore more engine power, better throttle response, easier starting and better fuel economy.

So we need an adaptor to get it to work, because the ignition would throw not one but several "sparks" out per stroke.

This is likely the cause of the higher shown rpm's on the little tach.

I don't know the fix for this problem, but that is likely the source of it. Maybe a call to the little tach company could produce a solution?

We may have to find a way to get into wiring of the flywheel pickup side of the ignition module to get a true one "spark" per rpm reading at all rpms.

This is really neat stuff to find out about the M=Tronic's, because the MSD was a great invention for hotrodder's/racers and emission thinking souls, it can also burn crappier fuel without as many issues, at least in cars it can.

I hope this is the "problem", because if it is, it is really neat that Stihl has come up with this tech for the saws.

Sam

 

[Stihlman441]

Thanks for that Sam,i dont realy need the tach as a rpm reading (cant change anything anyway) but it would be nice to see rpm in the cut,its mainly there for the hr reading so i hope that is correct.

 

[MCW]

Wonder if the M-Tronic system reads rpms in half-rpm, ie 2 per revolution. That way it would be twice as fast at adjusting the mixture, actually measuring accel/decel within the revolution? Anybody tached a 576AT?

Good point, but there would not be twice as many signals going up the spark plug wire ?.

Actually Officer's Match could be right as Slamm mentioned as well. The tach only has a 20,000rpm limit from memory so if the 441 hits higher revs there's a chance that it's stuffing up the tach somehow. Not sure but I'd say that's at least part of the issue.
Like I mentioned my Fast Tach struggled on the little 241C but did actually settle down eventually for a 13,600rpm peak no load.

 

[David (saltas)]

Andrew
I like your question because it was the complete opposite from what I expected
That worx connection tach works because it is unshielded

Unshielding the coil wire to get a strong signal that would swamp the reflection is what I expected to be asked.
The unshielding would be very bad for the "reliability in the quality" of the maths the electronics was doing to control the saw.

Might need to go old school and use an adjustable frequency strobe light (Stroboscope) on the flywheel

 

[Terry Syd]

I'm leaning towards Saltas view of the need for shielding for the electronic module. If the spark plug wire is some how shielded then perhaps wraps around the spark plug ceramic may work.

 

[Stihlman441]

I'm leaning towards Saltas view of the need for shielding for the electronic module. If the spark plug wire is some how shielded then perhaps wraps around the spark plug ceramic may work.

I may just try that thanks.

 

[David (saltas)]

I'm leaning towards Saltas view of the need for shielding for the electronic module. If the spark plug wire is some how shielded then perhaps wraps around the spark plug ceramic may work.

That is definitely worth a try and I'm interested if it works.

The ceramic is thicker and likely has a higher dielectric strength, the rubber boot goes sooooooooo far down the plug because this area is at the highest point of electrical stress i.e. at the termination of all high voltage cables.

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[albert]

The flywheel has two sets of magnets, Thats what is affecting the tach.