Another bad MS361 Ignition Module?

[HandLogger]

First things first, this is not an anti-Stihl thread. We've gotten great service out of our MS660s, our MS200T and our MS361. We also love our Dolkita 6421, but that's probably better off in a different thread.

Haven written that, it appears that we need yet another ignition module (aka, coil) for our circa 2007 MS361. This will be the third coil for this saw. Has anyone else had this kind of trouble with the [expensive] Stihl 1135-400-1300 ignition modules?

It would also be interesting to read if anyone has found a suitable substitute for this particular coil. I've seen aftermarket coils that are said to replace the Stihl 1135-400-1300, 1135-400-1308 and the 4238-400-1301 ignition modules; hence, the question.

Thank you for your time.

 

[lone wolf]

@pioneerguy600

 

[PV Hiker]

Would using a type of sparkplug that does not match coil cause the death of a coil over time?

 

[Wood Doctor]

Would using a type of sparkplug that does not match coil cause the death of a coil over time?

Likely the wrong spark plug would not kill the coil. The engine simply would not start or run correctly. I have encountered this a few times with owners who installed plugs they thought were superior to the plug that was recommended in the owner's manual. When I changed that plug out, the engine started and ran. It surprised me at the time, and the owner was rather astounded.

 

[TomW]

I also have had several coil failures in my MS361. Supposedly using a non resister plug can cause failure. The Stihl price for the coil is crazy. Presently I am using an import coil and it seems to work OK.

 

[a. palmer jr.]

I changed one out for a customer a few weeks ago. The one in my 361 is still working but I'll admit I don't use it much anymore.

 

[pioneerguy600]

I have seen a few failures in the modules myself on my own saws as well as saws owned by others. I have a feeling they were done in by heat affecting the electronic circuitry inside the module. I found that by running the saw for say 30 seconds to a minute after a heavy cut before shutting the engine off helped dissipate heat and prolonged the life of the modules. On one saw I have set up for milling it gets very heat soaked and requires even longer cool down times idling after a 16' long rip cut.

 

[lone wolf]

I have seen a few failures in the modules myself on my own saws as well as saws owned by others. I have a feeling they were done in by heat affecting the electronic circuitry inside the module. I found that by running the saw for say 30 seconds to a minute after a heavy cut before shutting the engine off helped dissipate heat and prolonged the life of the modules. On one saw I have set up for milling it gets very heat soaked and requires even longer cool down times idling after a 16' long rip cut.

You also have to keep the oil and dirt away from it ,clean it enough.

 

[pioneerguy600]

You also havd to keep the oil and dirt away from it ,clean it enough.

Clean is very good.

 

[Lightning Performance]

Had one coil fail in an 048. Updated it to an 029. Had to toss the key and back it up. She was running hot tuned fat. Handled a 36 bar like a champ.

Never had a 361 coil failure although they have come in in the past cooked and packed with junk. Anything you can bolt up that will fit will work. Not running resistor spark plugs is foolish if you can get them. They limit ignition noise. That must help the caps. A loosely fitting plug wire also takes its toll over time.

Oh, the AM coils are crap in many ways. Poor spark when hot is their worst offence. Number two is a wonky timing curve that jumps in large steps, not smoothly.

 

[Cedar Row]

I have seen a few failures in the modules myself on my own saws as well as saws owned by others. I have a feeling they were done in by heat affecting the electronic circuitry inside the module. I found that by running the saw for say 30 seconds to a minute after a heavy cut before shutting the engine off helped dissipate heat and prolonged the life of the modules. On one saw I have set up for milling it gets very heat soaked and requires even longer cool down times idling after a 16' long rip cut.

I have had coil problems also, on a 361. Have several coils, two of them are stihl coils, plus the one on the saw is Stihl. Have recently heard about the heat problem and letting the saw idle, especially after heavy cutting, from a somewhat arrogant Stihl dealer. Is there a way to check these coils other than reinstalling them on the saw? I assume that there is no way to create a spark except by having the coil spark activated by the flywheel magnets going by. And how about the credit card vs gapping tool conversation?

 

[The Shooters Apprentice]

Seems to be a common problem. I put a Farmertec coil in mine and haven’t had any issues with it yet. Been in there about a year.

 

[pioneerguy600]

I have had coil problems also, on a 361. Have several coils, two of them are stihl coils, plus the one on the saw is Stihl. Have recently heard about the heat problem and letting the saw idle, especially after heavy cutting, from a somewhat arrogant Stihl dealer. Is there a way to check these coils other than reinstalling them on the saw? I assume that there is no way to create a spark except by having the coil spark activated by the flywheel magnets going by. And how about the credit card vs gapping tool conversation?

The problem with checking out electronic modules is that even if the windings in the coil part check out for the correct resistance readings the module will not produce spark if the electronic circuitry is toast.The chip that produces the spark gets destroyed most times by heat and will no longer perform its task of switching on off, therfore performing resistance tests on the modules will not guarantee they will work. Mounting them back on the saw is the best way to see if they will produce spark or not. The gapping between the module and flywheel is not as critical as some would have you believe, .001 + OR - will not critically affect the modules ability to work correctly, a business card of around .010 works on all the Stihl saws I run even a difference of ,say its set at.012 the saw still performs reliably.

 

[belgian]

Yep, needed to change the coil on my 361 as well, after fairly low hours. It seems to be a weak component of the 361. Replaced it with an aftermarket one and it has run top since then.
Took me a while though to find out that the coil was the culprit. The spark plug would fire when tested outside the cylinder on the saw, but once under compression, the saw would not start. got me confused and put me on the wrong track for a while..grr

 

[Cedar Row]

The problem with checking out electronic modules is that even if the windings in the coil part check out for the correct resistance readings the module will not produce spark if the electronic circuitry is toast.The chip that produces the spark gets destroyed most times by heat and will no longer perform its task of switching on off, therfore performing resistance tests on the modules will not guarantee they will work. Mounting them back on the saw is the best way to see if they will produce spark or not. The gapping between the module and flywheel is not as critical as some would have you believe, .001 + OR - will not critically affect the modules ability to work correctly, a business card of around .010 works on all the Stihl saws I run even a difference of ,say its set at.012 the saw still performs reliably.

Thanks, Pioneerguy600,
As usual your comments are very helpful. I think the trick for keeping a coil working is to make sure to let the saw idle after cutting, especially after heavy cutting. I was also curious about the gap, you answered that issue well also.
Thanks again,
Cedar Row

 

[Old2stroke]

Not too relevant to this Stihl issue, but for what it's worth, here is another cause of coil failure.
When a spark event occurs, the high tension voltage increases until it arcs across the plug gap but when the arc is established, the voltage will not rise any higher. Any increase in the high voltage gap path will allow the voltage to increase until it arcs the gap, increased gap length may be due to wrong plug gap, spring clip on the plug not in contact with coil lead center wire, break in the lead wire, etc. If the gap is so large that an arc doesn't occur, the voltage can rise to the maximum the coil can deliver (plug lead disconnected) and this voltage might be high enough to break down the delicate insulation on the secondary windings of the coil and eventually lead to carbon traces and coil failure. This is the reason the engine should not be turned over fast with the ignition on and the plug cap off with no path to ground for the high voltage.

 

[KASH]

The voltage will not rise until there is a path to ground that is close enough for the current to bridge the gap to complete its path to ground.
Kash

 

[Old2stroke]

The voltage will not rise until there is a path to ground that is close enough for the current to bridge the gap to complete its path to ground.
Kash

Not true. If you want proof, just hold on to a screwdriver placed in the end of a disconnected plug cap and pull the engine over.

 

[KASH]

If you are insulated from ground you will feel nothing.Ever wonder how a tiny bird can sit on a 150000 volt hydro wire and fly away and do it time after time.
I am in full agreement with you that the saw will build up the voltage potential higher than normal but nothing happens unless there is a source to ground.
Kash

 

[cookies]

Keeping the saw clean is very important. Caked on sawdust mixed with oil insulates the heat in like a blanket. Storage of the saws in a environment that keeps them below 140f is also important. I have experienced failed coils on saws stored in a attic through a summer.