Stihl ms441, no start, weak spark?

[Mattyo]

Got an ms441 on the bench. 140 psi comp, piston looks ok, spark plug is wet with fuel. ...multiple times over.

no start.

I pulled the brandy new plug, and jumpered it.... the spark is blue but looks on the weak side..

do I ... #1 ...toss the saw in the river

#2.... pull the flywheel to check timing

#3.... swap the coil?

the coil is not shorted fyi...I checked

 

[Canadian farm boy]

My vote is to do option #2 first

 

[MustangMike]

I'd go for #3. A coil can be bad even when I sparks a plug.

I would only suspect #2 if the saw has been "played with".

140 is low, make sure your comp rel valve is not leaking and your plug is tight. The rings also may be worn.

 

[Evanrude]

#4... Check coil gap?

 

[Sty57]

#1
Set it free and see if it comes back.....then try to fix it.

 

[Mattyo]

Gap looks fine....not sure if I've ever gapped an ngk bpmr7a...they all seem to be ok from the factory.

I know 140 is a tad low....the saw does not have a lot of hours on it....plastics looks new for the most part.

Gotta call the local stihl dealer and see what they got for a coil.

 

[Evanrude]

Not the plug gap. I was referring to the coil to flywheel gap. Loosen the coil bolts then just put a business card between the flywheel and coil, spin the mag around to the coil and tighten the bolts. Remove the business card and the gap should be almost perfect.

 

[Mattyo]

ah, nice call, will check

 

[MustangMike]

Make sure the contacts are clean also, and while you are at it make sure the magnets feel strong.

Generally, put the magnets on the off side, insert the card, then rotate the magnet in line and tighten it up. A larger gap will retard timing, a smaller gap will advance it.

 

[Mattyo]

coil gap is fine, no start

 

[Mattyo]

the on off switch is doing its job.... no issue there....checked w/ my ohm meter

 

[Stump Shot]

See if it will jump a long gap of about 5/16" or so, it should spark a bright blue(fat), if it's fuzzy, white, pink or just plain old skinny and can barely see it, or nonexistent you have a bad coil. If unsure, try it with a known good saw and compare. If you have a good blue spark that will jump a gap, it should fire under compression, look elsewhere for your problem.

 

[Mattyo]

dealer price is $168 for a new coil

 

[Stump Shot]

Didn't Stihl have coils warranted forever or some such thing? Maybe someone here knows something about this, as I'm not real sure myself, just something I heard.

 

[MustangMike]

The AM one I got for about $15 for 044#2 works just great!

 

[Mattyo]

no am coil for 441

unless you know that an 044 coil fits.... but I didn't think so

 

[Canadian farm boy]

Did you check the flywheel key yet Matt?

 

[huskihl]

Are you sure it's not flooded?

 

[Mattyo]

I have not pulled the flywheel yet and I don't think it's flooded because we've let it sit overnight multiple times

 

[Stump Shot]

Took a couple of pics of a MS440 I have apart, you can see if the coils look similar and in the same place. If it looks good might be wort a shot, even if you had to replace the flywheel with it you'd be money ahead. The 044/MS440 coil is pretty common among Stihl saws, so not the worst thing to have laying around if it didn't pan out.

http://www.hlsproparts.com/stilhl-044-parts-s/87.htm