# Stihl HS45



## Bob970 (Sep 1, 2016)

Will not try to start, not even a pop. Good spark. Good compression. put gas in spark plug opening. Still won't even pop
Any help would be greatly appreciated


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## alexcagle (Sep 2, 2016)

Check your flywheel key that it's not sheared. Pull the plug, put a screwdriver on the piston top. After you find tdc, look at the magnet on the flywheel and see that it just leading the coil. If not then it's probably sheared.


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## Bob970 (Sep 2, 2016)

We put a new flywheel on. did notice a little play in both directions. I'll check at tdc and see where the magnets are. Thanks for your input

Bob


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## alexcagle (Sep 2, 2016)

When you put a flywheel on, it's important that the crankshaft hub taper and the flywheel hole be oil free. Use brake cleaner, laquer thinner, or acetone on a paper towel. When you tighten the nut, put some clean starter rope in the spark plug hole when the piston is about 1/2 way up. Leave the end of the rope hanging out; of course, for retrieval. Or ; if you are careful, you can use a screwdriver to keep the crankshaft from spinning as you tighten the nut by sticking the screwdriver between the coil and the flywheel magnet. Don't use a weak place, and break a fin off. Use a strong part of the flywheel. You need to get it gutentight too.


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## ANewSawyer (Sep 5, 2016)

What's gutentight mean?


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## arrow13 (Sep 5, 2016)

ANewSawyer said:


> What's gutentight mean?


That's "good and tight" in Norveegian


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## ANewSawyer (Sep 5, 2016)

But Alex isn't from norvegan.

Sorry to the op. I would replace the spark plug, or even swap for a known good one. It seems like someone on here metioned plugs not sparking under compression.


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## Bob970 (Sep 5, 2016)

Did that too. Thanks for the reply. All suggestions greatly appreciated


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## ANewSawyer (Sep 5, 2016)

My mechanical ability is small, I just leach off other peoples knowledge. Still, it should be running. @HarleyT @backhoelover 

Obvious question, how old is your gas? Ethanol or 100% gas?


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## Bob970 (Sep 5, 2016)

Fresh gas. 89 octane 2days old


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## CR888 (Sep 5, 2016)

Kill switch faulty?


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## Bob970 (Sep 6, 2016)

Disconnected it. This one is a tough one. I put tester on spark plug . Great spark. put some clean gas in spark plug hole. Will not pop. Compression is 140. No air leaks detected with block offs in place.


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## arrow13 (Sep 7, 2016)

How's your plug wire condition? Check for solid connections on both ends. I've had the prong set on the side of the wire core and not work well enough until I re-positioned it in the center. Got a better spark.
I also would check the wire for any cracks. I've had a saw start and run fine one day and not the next. It was shorting out through a hidden crack that was covered by a chafing shield where the wire went through the casing.


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## Bob970 (Sep 7, 2016)

I'll check that out today. Thanks.

I recently had an Echo trimmer with that exact situation


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## backhoelover (Sep 7, 2016)

When the plug is not in cylinder and not under compression it take a 1000 volts to fire plug. When the plug is in cylinder under compression it takes 10,000 volts crazy huh???


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## backhoelover (Sep 8, 2016)

What plug so you have in it


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## Bob970 (Sep 12, 2016)

backhoelover said:


> What plug so you have in it


BPMR7A

I took old flywheel and ground the key out. Then I compared flywheel magnets to coil on a Stihl blower. Set the flywheel the same on the HS45 and Voila , it runs fine. Got me. but it runs


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## backhoelover (Sep 13, 2016)

Glad you got it


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## WoodTick007 (Sep 13, 2016)

ANewSawyer said:


> What's gutentight mean?


Seriously?


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## ANewSawyer (Sep 13, 2016)

Yes, it was a joke. 

Op, glad you got it running!


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## Bob970 (Sep 13, 2016)

WoodTick007 said:


> Seriously?


Yes Seriously. Sometimes you have to think outside the box. McGiver it


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## arrow13 (Sep 13, 2016)

Bob970 said:


> BPMR7A
> 
> I took old flywheel and ground the key out. Then I compared flywheel magnets to coil on a Stihl blower. Set the flywheel the same on the HS45 and Voila , it runs fine. Got me. but it runs


Good to hear you fixed it. Thanks for letting us know.


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## davhul (Sep 19, 2016)

When was last time it was running?Carb could be flooding the engine.


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