High Quality Chainsaw Bars Husqvarna Toys

No Spark, Now What?

Fairways_and_Greens

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My wife has a Sithl MS150 that I muffler modded and advanced the flywheel. It ran awesome, but occasionally after being ran and then turned off, it wouldn't start again. Now it won't start at all.

I couldn't see any spark so I put the flywheel back to nominal and then hooked it up to my multi-meter. It would detect a little electricity, but erratically.

Any advice on where to go from here? Wifey is pissed that her baby is in pieces.
 

MG porting

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My wife has a Sithl MS150 that I muffler modded and advanced the flywheel. It ran awesome, but occasionally after being ran and then turned off, it wouldn't start again. Now it won't start at all.

I couldn't see any spark so I put the flywheel back to nominal and then hooked it up to my multi-meter. It would detect a little electricity, but erratically.

Any advice on where to go from here? Wifey is pissed that her baby is in pieces.
Like smokey 7 said and if that changes nothing then check coil wire if that terns out to be fine then most likely a plane bad coil it happens.
 

AlfA01

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I'm thinking that the coil is probably shot. Not firing after it's hot is indicative, albeit not inclusive, to an imminent coil failure or coil wire that has too much resistance. As others said above, the first thing to always check is that the kill switch is not causing the problem. By removing that wire from the coil, the circuit for the switch is isolated. If the saw operates normally, then you need to replace/repair the switch, or wire to the switch.
 

Fairways_and_Greens

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I'm thinking that the coil is probably shot. Not firing after it's hot is indicative, albeit not inclusive, to an imminent coil failure or coil wire that has too much resistance. As others said above, the first thing to always check is that the kill switch is not causing the problem. By removing that wire from the coil, the circuit for the switch is isolated. If the saw operates normally, then you need to replace/repair the switch, or wire to the switch.

How would I test a coil wire failure vs replacing the coil?
 

jacob j.

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How would I test a coil wire failure vs replacing the coil?

Typically by replacing the coil wire with a new assembly.

How much did you advance your coil? These newer coils don't seem to be standing up to running advanced, especially in the smaller saws.
 

angelo c

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maybe get another coil ?
my media cat is old. no 150c. sorry.
maybe somebody can run a newer version and find out if the coil is common to another more popular coil so you can swap and check ?
"where used" function
 

Stump Shot

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You may try unhooking the kill wire directly from the coil itself instead of the switch, as it may be shorting somewhere along its route. If the spark wire is in good shape then "most likely" you have a coil gone bad and need to replace it. Oh and Happy Birthday @Fairways_and_Greens
 

Fairways_and_Greens

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Typically by replacing the coil wire with a new assembly.

How much did you advance your coil? These newer coils don't seem to be standing up to running advanced, especially in the smaller saws.

I advanced it maybe 3 to 5 degrees. I put it back to nominal once I started troubleshooting. What is the significance of the yellow paint over the magnets?
 

Fairways_and_Greens

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I just had the exact same failure... Very frustrating. I was checking out @Stump Shot 's video regarding the flywheel. I checked my flywheel and it's sheered. I tried moving it over and it ran like in the video below. If the timing is too far off will no spark go to the plug? I thought it would have spark, just at the wrong time?

 
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Stump Shot

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I just had the exact same failure... Very frustrating. I was checking out @Stump Shot 's video regarding the flywheel. I checked my flywheel and it's sheered. I tried moving it over and it ran like in the video below. If the timing is too far off will no spark go to the plug? I thought it would have spark, just at the wrong time?


If too far off it won't run at all.
 

jacob j.

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On the older saws, the coil would make spark regardless of the timing position of the flywheel on the crank. I don't know about these newer computer-controlled machines.

Of course in newer cars/trucks, they go right into a no-start condition when something like the ignition timing is askew.
 

Stump Shot

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Cut a groove where the key was and slide in some copper or something else on the soft side?

Kind of on your own there, I would be replacing the flywheel if it has a cast in key.
That said, theoretically speaking, if you can get it set where you want it should stay. At least this would give you a heads up to possible other problems or not.
I have to say I am curious as to the no spark situation you are experiencing.
 
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