Stihl 034....Inconsistent spark

[farmin68]

New to this site and I already love it!

I'm hoping someone on here can help...My 034AV won't start. I've tried new spark plugs and adjusted the module/flywheel gap. I've had this saw for several years and now it seems to have more compression than in the past.

With the spark plug out and attached to the plug wire, I only see sparks on occasion (probably 2-3 times in 20-30 pulls on the rope).

This problem started a few months ago. After it finally started, it ran fine and would restart fairly easily as long as the engine was still warm. Worked with it til I was exhausted yesterday. It ALMOST started one time.

Any ideas or suggestions will be appreciated.

 

[THALL10326]

New to this site and I already love it!

I'm hoping someone on here can help...My 034AV won't start. I've tried new spark plugs and adjusted the module/flywheel gap. I've had this saw for several years and now it seems to have more compression than in the past.

With the spark plug out and attached to the plug wire, I only see sparks on occasion (probably 2-3 times in 20-30 pulls on the rope).

This problem started a few months ago. After it finally started, it ran fine and would restart fairly easily as long as the engine was still warm. Worked with it til I was exhausted yesterday. It ALMOST started one time.

Any ideas or suggestions will be appreciated.

Check all your wiring, can't have any cracks. Make sure your conections are clean, no corrosion at the coil itself. Check your spring inside your spark plug boot, need to make sure its not rusted away and that its plugged in good to the spark wire itself. The boot needs to be in tact too, no splits. May want to try another spark plug, they do go bad. I've gotton brand new ones out the box that would not fire. Make sure the gap you set the coil at is correct. If its too wide you will get a erratic spark.

Finally and foremost, the coil. Seeing a spark at the plug laying on top of the cylinder is not a good indicator of a hot spark. The coil has to be able to fire that plug under compression, takes more voltage to do that. Check all the above and if all is good its 0000-400-1300 for you, thats the coil number by the way.

 

[Bowtie]

That saw is junk, parts saw. I'll give ya 25 bucks for it, hell, I'll even pay shipping. Just kidding, I have a 034 and I love it. You will figure it out, keep plugging away, these experts on here are awesome at helping guys like us out that have problems with our toys...I mean saws.

 

[Lakeside53]

Everything Thall said...

Open your TEST plug gap up to about 3/16 to 1/4 inch... or just bend up the ground electrode vertically.. Then you'll be simulating the voltage needed to fire under load. WIRE the plug body to the cylinder (or use a couple of big battery terminal clips)- not just trying to touch it to the cylinder ground...


If you are the original owner, the coil is covered by warranty. If not... you'll likely be buying one. A used coil goes for about $35 (and is very common - on many Stihl saws); new is $104..

 

[Timberhauler]

I had an 034 that I ran for years before my business grew so big....The coil went bad in mine after about four years..I changed the coil,ran the saw another year or so,then gave it to my dad.That was seven years ago,and he still has the saw,and it still runs well.Though it has had a new top end since then as well.