MS661 -- No Spark
- Thread starter PogoInTheWoods
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New micro-switch, no joy. I am ready to give up, and return the saw, without payment. Its clear to me, Auto--tune, and M-tronic, are equally junk......I won't touch an M-tronic on a bet as of Monday. German engineering. A fuel injected, computer controlled, chainsaw? Really?
Valve 0000 120 5110 (black) is replaced by 0000 120 5111.
Good morning, sir. I was hoping you would drop in again! And thank you for the part number. Any chance you may also have the TI for its release?
Yeah, really.
So here's the deal..., and a couple more observations.
You are missing something in the physical inspection of your work or not following the service manual ignition testing instructions exactly as prescribed. Don't be intimidated by references to the MDG1 system thinking you're ill-equipped to troubleshoot the system without their magic box. You aren't. A multi-meter will do just fine with some common sense and basic understanding of what it is you are actually testing and what the desired results should be. There are only so many things that could be wrong -- all of them very simple to determine. Spark. Voltage. Wiring Integrity.
Start by doing a continuity check from the plug wire boot connection to ground with the control lever in the 'run' position. Should be open / infinity. If open, test again while holding the control lever in the stop position. Should be a dead short to ground. If both of those conditions are met, the kill switch works as it should and the short circuit wire is doing its job. (And bear in mind that the position of the control lever has everything to do with the particular test you may be doing on the wiring or components and that the carburetor and switch need to be installed correctly for the switch to be activated by the arm on the carb when the control lever is put into the 'start/choke' position.)
Now pull the plug (a new one) and short it directly to the cylinder by means of a screwdriver or plug wrench (to avoid sparkover igniting any fuel spillover from the cylinder) and check for spark with the control lever in the 'start/choke' position. This eliminates your spark testing method or tester as a potential issue in all this. Pull briskly or use a drill in reverse on the flywheel nut as suggested. You can't just pull over an MS661 like an old lawn mower and expect spark. The flywheel needs some RPMs to give you sh!t for spark. If no spark, go back to the shop manual and start over beginning at page 41 for a complete understanding of the ignition systems and the methods and objectives for trouble shooting and repair. Don't just skim over it. Read it thoroughly. Understand it. Follow the instructions. You've already thrown all the parts at it. Pretty good chance they're not the cause of your current frustration. Then again, you could start replacing all of THEM too just to cover all your bases and continue to blame German engineering. LOL
Nah. You'll get it. Way too much into it to give up now. But depending on where you are in Michigan, you have an open invitation to bring me the saw if you're at your wits end and we'll get it sorted out together....6 feet apart, of course.
Or hell..., just try to fire it up. It may actually start.
Ok re-read this and just pointing out how it worked for THIS 201TC. Three attempts at "Factory Reset" WITHOUT BAR were not successful. ONE "Factory Reset" with bar and chain resulted in success. May very well be random...
My focus here is to ATTEMPT to make this procedure as dirt simple as just you described above....( apply in field in different languages)
So if I am reading this correctly (and I may NOT be).... not matter WHAT version a 90 sec start on "CHOKE-Fast idle" without any contact without bar and chain will reset ECM to factory...followed by a ( MAY or may NOT be necessary ) waiting period of a few minutes.... then a 30-60 sec WOT run listening for the RPM variations and ultimately a smooth running saw with BAR and Chain. It shouldn't matter what V you have as you are performing BOTH recalc/resets for both Versions and neither is damaging to the saw or firmware.... am I reading proper ?
That's pretty much it.
For the sake of accuracy, (and a disclaimer), I was just going to comment on this again anyway. First, it's my understanding that a literal factory reset of the ECM requires the MDG1 system..., as in wiping it clean of any unit-based 'learned information' history. This would apply to any version of firmware. As for the 90 second field 'factory reset' procedure without bar and chain, I read that TI as applying to v2.1/v3.0 ECMs as the only requirement for returning to normal operation after replacing a solenoid -- no full blown calibration with bar and chain necessary.
My two main points were that there are only two actual field procedures to set up an M-Tronic saw. One is for v1.x, the other for v2.1/v3.0. Both require a bar and chain. The other point was that the procedure not using a bar and chain was simply a square one process for recognition of a new solenoid..., which I understood to leave the other data in the ECM alone and it would adjust accordingly to any new mix requirements when operated with a bar and chain under normal cutting conditions. I was only addressing the v2.1/v3.0 systems based on the particular TI indicating the bar and chain were not required for that process. Later TIs (including the one posted earlier) call for a re-cal of either system with bar and chain when any M-Tronic component is replaced. I've not heard or read anything to the contrary since that publication.
No earth shattering info on the green solenoid, btw. The white one is still the preferred replacement for v3.0 systems. Evidently the green one shipped for a period of time on ZAMA carburetors according to a source I spoke with this morning, but he wasn't even sure about that. Just indicated there were some random ones out there and he hadn't heard anything new regarding their availability or purpose other than they were originally supposed to be an improved version of the black ones and a universal fit for all applications as was rumored a couple years ago..., which fits the time frame of toadman's saw. It does not show up as an active part number and I'm guessing the white one would be the current replacement.
For the sake of accuracy, (and a disclaimer), I was just going to comment on this again anyway. First, it's my understanding that a literal factory reset of the ECM requires the MDG1 system..., as in wiping it clean of any unit-based 'learned information' history. This would apply to any version of firmware. As for the 90 second field 'factory reset' procedure without bar and chain, I read that TI as applying to v2.1/v3.0 ECMs as the only requirement for returning to normal operation after replacing a solenoid -- no full blown calibration with bar and chain necessary.
My two main points were that there are only two actual field procedures to set up an M-Tronic saw. One is for v1.x, the other for v2.1/v3.0. Both require a bar and chain. The other point was that the procedure not using a bar and chain was simply a square one process for recognition of a new solenoid..., which I understood to leave the other data in the ECM alone and it would adjust accordingly to any new mix requirements when operated with a bar and chain under normal cutting conditions. I was only addressing the v2.1/v3.0 systems based on the particular TI indicating the bar and chain were not required for that process. Later TIs (including the one posted earlier) call for a re-cal of either system with bar and chain when any M-Tronic component is replaced. I've not heard or read anything to the contrary since that publication.
No earth shattering info on the green solenoid, btw. The white one is still the preferred replacement for v3.0 systems. Evidently the green one shipped for a period of time on ZAMA carburetors according to a source I spoke with this morning, but he wasn't even sure about that. Just indicated there were some random ones out there and he hadn't heard anything new regarding their availability or purpose other than they were originally supposed to be an improved version of the black ones and a universal fit for all applications as was rumored a couple years ago..., which fits the time frame of toadman's saw. It does not show up as an active part number and I'm guessing the white one would be the current replacement.
My guys didnt know jack diddly squat about the new solenoid nor did the PN come up as "active"..
Standing by...
As I mentioned, the part number didn't come up active for me either.
I don't think the 5111 is actually new, but rather was a limited implementation as a hopeful upgrade remedy for 1.x systems along with also being rolled out in early v.3 MS661 systems prior to the introduction of the white solenoid. (My memory is coming back to me after speaking with a dealer friend who was the source of some of my initial information a couple of years ago -- right around the time toadman's saw would have been produced.)
Our mutual info source indicated back then that there were vendor problems and production issues with the 5111's and Stihl opted out of that arrangement in favor of what became the current white v3.0 solenoid solution. If that story is legit, it's highly unlikely 5111's are in production again or even on a shelf anywhere. They were obviously produced in the past as proven by toadman's saw.
Sorry for all the unnecessary excitement. I've heard about the phantom green miracle solenoid for so long I got carried away finding out there actually was one. LOL
So back to the Captain getting the problem MS661 running...
I don't think the 5111 is actually new, but rather was a limited implementation as a hopeful upgrade remedy for 1.x systems along with also being rolled out in early v.3 MS661 systems prior to the introduction of the white solenoid. (My memory is coming back to me after speaking with a dealer friend who was the source of some of my initial information a couple of years ago -- right around the time toadman's saw would have been produced.)
Our mutual info source indicated back then that there were vendor problems and production issues with the 5111's and Stihl opted out of that arrangement in favor of what became the current white v3.0 solenoid solution. If that story is legit, it's highly unlikely 5111's are in production again or even on a shelf anywhere. They were obviously produced in the past as proven by toadman's saw.
Sorry for all the unnecessary excitement. I've heard about the phantom green miracle solenoid for so long I got carried away finding out there actually was one. LOL
So back to the Captain getting the problem MS661 running...
Poge, and Tom82, and the other saw guys who chimed in......THANK YOU. The 661 is running, completed, re-calibrated, and ready for its mill.
This has been a learning experience in so many ways,,,, not the least being arborsite. Hopefully, I have gone from knucklehead to humble, and am wearing my rank again.
Ahhhhhh what was the final "fix"...we all wanna know so we all lern
That depends. If all it needed was a new plug, you're gettin' thrown overboard! LOL
It was the very first thing you suggested I check; wiring. Regardless, once the saw was back together with all new A/V mounts, from log roll that wiped out the clutch cover and handle.................I got it fired up, only to damage the coil wire. Maybe it was already chafed. Poge explained the logical repair; the up-grade kit. Replacing a 4700 coil, was wrong. I was directed to the up-grade kit; 4704, orange filter, and white sole.
While I had the carb off, I checked every wire for resistance. No spark. Next I purchased a new wiring harness, and stripped the saw again. Once back together....No Spark.
Now I learned how to test the micro-switch diode.........and got nothing. New switch, more money. Put it all back together, and No Spark. So I tested the yellow grd. wire again...removed the screw, isolated the wire, and got nothing. Put the VOM probe to the exposed wire? no resistance. The eyelet? open circuit? So, I pinched the yellow wires eyelet tighter, put it back the the chassis, put the screw back in, turned out the lights.........and made lightning bolts from the tester.
Put the covers back on, wiped it 1 more time, put the re-cal. instructions on the bench. Mounted a NIB 28" set-up. Choke, de-comp., first pull............and it barked. Set the brake, started it on 1 pull, let it slog along for 45 sec., and than released the brake, went to WOT, by the clock............what a moment. At 25 sec., the engine smoothed right out, and roared spot on.
Again, Thank You, Captain B. Bart
Congratulations, sir.
I just posted it. Saw needed up-grade kit due to bad coil. Micro-switch turns out was also dead = diode. Wiring tested good......until I found the chassis eyelet for the yellow ground wire, was poorly crimped. This project req'd $250 ignition in parts, starting with the log crush damage, and ending with a NIB Stihl harness, with a loose connector.....................the re-cal. process is a rush!Ahhhhhh what was the final "fix"...we all wanna know so we all lern
THIS is why I will always bow to Arborsite.
Tom82
ArboristSite Operative
Just for reference:
I didn't necessarily think the coil was bad but, it gives you a new coil, plug wire with boot and spring + a fuel filter and fuel solenoid.
Also, the idea behind replacing the coil while it's being serviced is because the early mtronic in the 661 (or in general) is unreliable and has lead to failures many times, this is the reason the repair kit exists. If you would have had a 4701 coil, you could have possibly needed a fuel solenoid but, at least the 4701 was a more reliable coil.
I definitely don't believe in throwing parts at something to hope it works but, these parts are known problems so, spending money to eliminate current and future headaches is beneficial is this instance.
Hope this clears up some of my recommendations.
Absolutely TOM! When the exercise started, it was a expensive chainsaw, that was busted up........can you fix it? Money is no object. I went in with guns blazing, and came out a better mechanic. The coil lead, upon inspection, under a magnified lamp, showed the casing to be worn thru, While I understand that older coils and solenoids can be just fine, once the replacement was expected, the kit was the direction to go. Someday, after the Summer, I am going to dig deep into M-tronic. Can a shorted out coil destroy the solenoid, mirco-switch, etc>? Can a bad/dirty solenoid cause the ignition to stop spark? Does the mircro-switch become an integral part of the electronics, or just when activated, to provide choke? For now, I am going to go sit on my Boat for a few days, and not have this worry. Thanks Tom.
Tom82
ArboristSite Operative
Haha, no problem.
Solenoid is an output transducer. It's circuit should be isolated from the input circuit. So data collected from various sensors are analyzed and the results will be output to give a desired result based on data collected. It's that simple -_-
Solenoid is an output transducer. It's circuit should be isolated from the input circuit. So data collected from various sensors are analyzed and the results will be output to give a desired result based on data collected. It's that simple -_-
Lawless crf
044REX
I just Burnt a 4702 coil the new one I got is 4704.
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