# Stihl chainsaw won't fire



## mjw2025 (Jul 24, 2008)

I have a Stihl chainsaw that has only about 10-15 hours of running time on it. It had been sitting in my garage for about a year and a half with old fuel. I should haven't keep the fuel in it but replaced it with a new mixture, checked the fuel filter and it was clean, and it refuses to fire. I replaced the plug in spite of the fact that the original looked ok and showed spark and it still won't start or even give an indication of firing. I then put about a tablespoon of gas in the cylinder without any hint of firing. There isn't any physical damage to it and it feels like it has good compression. The last time I did use it starting was effortless and now nothing. I'm not a small engine genius but two cycle engines aren't that complicated. Does anyone have a suggestion?


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## 30yearTech (Sep 14, 2006)

What model chainsaw do you have??


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## mjw2025 (Jul 24, 2008)

It's a MS290 "Farm Boss".


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## luckyvision (May 24, 2007)

check for loose case/cyl bolts or a sheered flywheel key.
is the plug wet?

if you bought it new, or transfered the warrenty, & it's under a year old (homeowner use) it is under warrenty, (gummed up carbs are not covered)

--Lucky


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## justin3 (Apr 10, 2007)

Its possible you flooded your engine with the tablespoon of gas u put in the cylinder. Let it sit for awhile with the plug removed to dry out the cylinder. Also a good idea to replace the spark plug while your at it.


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## luckyvision (May 24, 2007)

yeah, a shot of carb cleaner in the carb or plug hole is usually sufficent to get it to kick...


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## mjw2025 (Jul 24, 2008)

Although it's about three years old, operationally it's almost new as I have relatively few hours of running time. The last time I used it starting was similar to when it was brand new so I don't think it's something such as the flywheel key. My thoughts, as suggested here, is that I'm flooding it so I'm going to give the techniques suggested her a try. One suggestion was shot of carb cleaner in the cylinder or carb and my question is if carb cleaner is similar to starting fluid? The reason I ask it that I've read that starting fluid can be pretty hard on the engine.
Thanks


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## luckyvision (May 24, 2007)

starting fluid is straight either & will wash the oils off the cyl walls, carb cleaner contains oils & won't harm the cyl as long as you don't 'run' the machine off it.


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## mjw2025 (Jul 24, 2008)

I finally got around to trying your suggestion and it worked.
Thanks


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## COMP (Jun 11, 2008)

mjw2025 said:


> I finally got around to trying your suggestion and it worked.
> Thanks


so what was it ??


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## mjw2025 (Jul 24, 2008)

It was squirting carb cleaner into the cylinder. My response was directed to Luckyvision, who suggested it, but I forgot to specify. I appreciated everyone else's help too.


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## COMP (Jun 11, 2008)

mjw2025 said:


> It was squirting carb cleaner into the cylinder. My response was directed to Luckyvision, who suggested it, but I forgot to specify. I appreciated everyone else's help too.


:thumbsup:


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