Sthil fs 85 will not start

wvjack

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Trimmer wouldnt start last spring, Put new Carb. on it an it still wouldnt start. It is about 7 yrs old and heavy so I bought new one, Fs 45, Its lighter an easier on the back. I have started working on the 85 again. It has fire but dosnt look very strong, it gets Fuel but no luck, Ive even used starting fluid an it dosnt start.

Any help will be appreciated....
 

whelch1

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I had a problem with my fs-45 starting this past week. I was able to change my carb and it worked. I did however read about a screen in the muffler that will plug up and cause problems.
 
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EngineMan

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I would also check the coil.
 

bertsmobile1

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Pull the starter off and check that the flywheel is still in the right position.
Other than that it should start if you spray fluid down the plug hole or carb.
If it starts with fuel in the plug hole but not directly through the carb then either the rings or the crank seals are cactus.
 

wvjack

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I would also check the coil.

as i mentioned in post Spark looks weak. How do i check to see if coil is causing weak spark. The plug is good, it started a chain saw
 

EngineMan

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as i mentioned in post Spark looks weak. How do i check to see if coil is causing weak spark. The plug is good, it started a chain saw

I've sent you a message.
 

bertsmobile1

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I've sent you a message.

Sparks on 2 stroke saws & blowers etc that run at 10,000 plus RPM will usually appers to be weak at cranking speed.
I use a neon plug tester rather than looking for a spark at the plug.
 
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