Stihl Chainsaw Won't Start

[Larry Frank]

Ok had a Stihl for years and drained gas every year. It seemed harder to start every year and I got older and my shoulder sorer. I sold my Stihl and bought an Ego battery one. It cuts great and starts easy .

[Bill George]

Well despite fresh gas mix, new plug, removal of the spark arrester screen and new carb still no start. I even tried another coil and that did not help so back to the OEM. I think it has to do with timing and I found info online that suggests that the key way might be compromised. There is also info regarding altering the timing on this engine to increase the output power. I will get into that later on as this project is going on hold as I have other things to get done.

[Edward Weber]

The distance of the coil from the flywheel will effect the strength of the spark. The key way on these saws has been described as "notoriously" sloppy, + or - 5 degrees in some descriptions.
the combination of these things can certainly 1. provide spark, 2. fail to start.

[Bill George]

From what I found out the gap or distance also has some effect on the timing. The magnets are marked N & S for a reason that needs looking into when I get more time. Right now we are headed toward a early spring.

[Tom M King]

Might be worth pulling the muffler and locking at the piston. https://www.youtube.com/watch?v=Iay9-rmhWEA

My next step would be a pressure test. Might just be a leak in the impulse line, but could be other places too. I doubt it's anything to do with timing.

[Bill George]

Might be worth pulling the muffler and locking at the piston. https://www.youtube.com/watch?v=Iay9-rmhWEA

My next step would be a pressure test. Might just be a leak in the impulse line, but could be other places too. I doubt it's anything to do with timing.

I had it, off piston looks fine, and good compression. Lots of experience with both 2 and 4 stroke engines. Its getting gas , plug shows that, but no fire at the right time or not hot enough spark causes it not to start.

[Edward Weber]

I had it, off piston looks fine, and good compression. Lots of experience with both 2 and 4 stroke engines. Its getting gas , plug shows that, but no fire at the right time or not hot enough spark causes it not to start.

While I don't typically recommend products, I strongly suggest an NGK spark plug.

[Bill George]

While I don't typically recommend products, I strongly suggest an NGK spark plug.

That was replaced first and always a NGK.

[Tom M King]

I had a friend a long time ago that raced motorcycles. One of his sponsors was Champion sparkplugs. I saw him one night repainting some sparkplugs and doing a pretty good job of putting Champion on them.

[Bill George]

Went out to do some checking on the saw and this time found NO Spark, WT heck!! Always had it before?? So I put on the Made in China coil that I had and did not use because it Had Spark. After a few pulls and now starts and runs. Headed out to cut off a stump so I can get the mower back in that area. I did no adjustments to the Chinese Carb I put on a week or so ago. Never had a problem with the better grade of Chinese carbs I buy.










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[Tom M King]

Glad it was something simple and you got it back to work.

[George Armstrong]

What should the gap be on the coil?

[Tom M King]

Different saws ask for different gaps but if I'm remembering correctly Stihl saws call for .2MM to .4MM depending on the saw. Bigger saws with stronger coils use the larger gap. I have two different gauges that cover my three saws. Some people use a new dollar bill but that always seemed like it had a guesswork factor to me.

[Bill George]

I went by what Chickanic put in her video , business card. The one I used measured about .014 inch or .35mm . It must fit under both poles of the coil. I use premium grade non Ethanol gas, with Stabil unless I know I am going to use it right now.

I am going to guess since the OEM coils are replaced by the thousands, they have a design or manufacturing issue.