no spark

[petefran]

my ms362 2009 model has no spark. I tried a Chinese one that was compatible ran for 5hrs now nothing tried new plugs nothing tested all wiring all good put the drill on fly wheel nut still nothing could it be the fly-wheel magnets weak no bearings gone all perfect looking forward to replies thanks petefran

 

[pioneerguy600]

After checking all the obvious reasons for no spark it comes down to the module being defective, the AM modules are a crap shoot, some work, some work for a while and some don`t work at all. It`s a very rare case the magnets are weak on a saw that new, my own 362 has gone through two OEM modules, they just lost spark without no warning , worked one day but not the next.

 

[Mad Professor]

After checking all the obvious reasons for no spark it comes down to the module being defective, the AM modules are a crap shoot, some work, some work for a while and some don`t work at all. It`s a very rare case the magnets are weak on a saw that new, my own 362 has gone through two OEM modules, they just lost spark without no warning , worked one day but not the next.

Remember when.....Stihl ignitions were lifetime warranty?

 

[Wood Doctor]

Interesting thread. I just replaced the ignition module on a Stihl 193T, a saw that looked brand new with very few hours on it. It also had no spark and the plug was fine. With the new IM on board it started and ran like a top. The owner had store it for two years in the garage. Almost no tune up was required. I told him that perhaps the IM was defective to begin with. Not sure what would have killed it. Sorry that I have no Pics.

 

[Chevboy0167]

I will venture to say that the capacitors in the module go bad from age, heat and physical damage like cracking. It's not like the manufacturers are going to use "the best" most reliable and more expensive components if the cheap stuff last a couple of years of service.

 

[hotshot]

ESR? Had to look that one up…

Equivalent series resistance (ESR), also known as internal resistance, is a value representing the loss of useful energy in a simple electronic circuit consisting of a resistor and an ideal (perfect) capacitor. Technically speaking, the energy is not lost but is usually dissipated as undesirable heat.Aug

 

[Sidecarflip]

Seems as though caps aren't as good as they once were (probably coming from China. I've had to replace 4 in the last 6 months, all double cap start-run compressor motors. They don't swell up or leak, they just fail. Thank goodness for Digikey.

 

[Chevboy0167]

I replaced 2 camper AC caps this yr and the 2 in my 2 stage air compressor last yr. The AC unit caps were China and the air compressor were original Baldor that lasted since 1996 when I got it new! Btw... only 1 cap tested very low for the compressor.....

I went with Baldor again in the air comp. and went with Amrad US made caps for the AC units. Much happier now. Even removed the hard start kit on 1 of them. No need....

 

[Chevboy0167]

On older electronic coils, they used electrolytic caps. Failure modes below...




On newer surface mount caps.....





Same outcomes..... no more spark.

Also, the switching transistors can fail.

 

[HarleyT]

Drills won't spin fast enough, and these newer modules put out a faint spark.

 

[aokpops]

I use to blow out coils fast at a rate of 30 minutes. I only use resister spark plugs never had any more trouble. The worst is when a nice blue spark an the engine will not run. From what I read and experience a nonresistant spark plug WILL knock the coil out of time. I bought OEM and aftermarket made no difference.

 

[SteveSr]

Seems as though caps aren't as good as they once were (probably coming from China. I've had to replace 4 in the last 6 months, all double cap start-run compressor motors. They don't swell up or leak, they just fail. Thank goodness for Digikey.

Get some good compressor caps from a good vendor like Am-Rad (American Radionics) They make Mil-spec caps and know how to make wound capacitors of various dielectrics.

 

[SteveSr]

I use to blow out coils fast at a rate of 30 minutes. I only use resister spark plugs never had any more trouble. The worst is when a nice blue spark an the engine will not run. From what I read and experience a nonresistant spark plug WILL knock the coil out of time. I bought OEM and aftermarket made no difference.

The resistor is there primarily for EMI (radio noise) suppression. Spark plug type shouldn't have any effect on a properly designed ignition module.

 

[SteveSr]

I will venture to say that the capacitors in the module go bad from age, heat and physical damage like cracking. It's not like the manufacturers are going to use "the best" most reliable and more expensive components if the cheap stuff last a couple of years of service.

View attachment 1110863

After spending a career as an electronics engineer this quote is mostly garbage. It conflates ceramic MLC capacitors with electrolytic types that are not even similar and have vastly different failure modes.

 

[ZeroJunk]

I may replace one Stihl ignition module a month versus eight or ten carburetors a week.

 

[aokpops]

The resistor is there primarily for EMI (radio noise) suppression. Spark plug type shouldn't have any effect on a properly designed ignition module.

I know that should not matter the worst was predator engines 20 minutes engine stop running no spark a no resistor spark plug. I do not! run a small engine repair shop I just fix what I own . And let people read what I experience.

 

[HarleyT]

Or he could test the coil properly.

 

[SteveSr]

I know that should not matter the worst was predator engines 20 minutes engine stop running no spark a no resistor spark plug. I do not! run a small engine repair shop I just fix what I own . And let people read what I experience.

Predator=Chinesium.

Non-resistor plugs increase peak secondary coil currents that can couple into the low voltage circuits causing temporary upset or electrical over-stress which can eventually kill components, especially semiconductors.