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Hi all, i have a Stihl hs 74 hedge cutter and the starter spring went, i got a new spring fitted it but that went also so i purchased the whole starter unit and that is fine now but it wont start, does not even try, there is a spark and after trying to start it if i remove the plug it is wet with petrol. I have put a new plug, air filter and fuel filter on it still no luck though. It has good compression. Any ideas?

Test the coil.

Hi EngineMan, thanks for the reply, how do i `test` the coil please?

A quick test with the multimeter will show that if there is continuity between the low tension terminal (which is used to switch off the engine) and earth, its gone and should be replace.

You may like to just remove that wire (switch wire) to see if it will start before you replace.

Thanks very much EngineMan, i will give that a try, if that has gone would it still spark ok?

Bootsy said:

Thanks very much EngineMan, i will give that a try, if that has gone would it still spark ok?

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You maybe able to see a spark, but its a "Stihl" so test it, if its gone, its gone...!

Hi, there are two wires that conect to the coil, both go to the on/off switch, both terminals on the coil show a short to ground. I have removed both conections and will put it back together and see if it works, will post results later. I expect that this means the coil needs replacing? Thanks for the help Mr EngineMan.

Wont go with both leads off.

Bootsy said:

Hi all, i have a Stihl hs 74 hedge cutter and the starter spring went, i got a new spring fitted it but that went also so i purchased the whole starter unit and that is fine now but it wont start, does not even try, there is a spark and after trying to start it if i remove the plug it is wet with petrol. I have put a new plug, air filter and fuel filter on it still no luck though. It has good compression. Any ideas?

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Yeah remove the shroud and look at the muffler, should be a small plate that you can remove. Under the plate is the spark arresting screen remove it and clean and see if that helps, if that thing is plugged you'll have a wicked time trying to start the machine.

Thanks for the reply Ric, i checked that and it was a bit dirty but even if i left it out it does not even try to go, very strange as its been a very good machine working fine then nothing. Think i will have to put it in a repair place.

Bootsy said:

Thanks for the reply Ric, i checked that and it was a bit dirty but even if i left it out it does not even try to go, very strange as its been a very good machine working fine then nothing. Think i will have to put it in a repair place.

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Let me ask and this is just a suggestion but does it have a primer bulb? If it does check the thing and see if it's cracked or has a hole in it. I had a trimmer that wouldn't start and I did about everything you have done and found the primer bulb had a crack and after I changed it the trimmer ran great. It's only a suggestion but sometimes we tend to over look the simple things.

Never been big fan of stihl. They flood out real easy when starting,,in my opinion.
If you have spark try this with a good dry plug.
Pump the ball few times. Then choke the machine and pull 3 times. Shut choke off and pull like 20 times. Turn choke on pull 3 times. Turn off pull 20 times. Keep trying that. Pattern. If it fires turn the choke off and rev it up a little while you pull.
Good Luck!!
Tanman34fl

tanman34fl said:

Never been big fan of stihl. They flood out real easy when starting,,in my opinion.
If you have spark try this with a good dry plug.
Pump the ball few times. Then choke the machine and pull 3 times. Shut choke off and pull like 20 times. Turn choke on pull 3 times. Turn off pull 20 times. Keep trying that. Pattern. If it fires turn the choke off and rev it up a little while you pull.
Good Luck!!
Tanman34fl

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There is something wrong if you have to pull anything 20 times to start it, let alone another 20 times....!

Thanks for all the replys, still no go, it wont fire at all. Primer bulb is ok and full of fuel. I think maybe as it just stopped working ie no bad runing ect just stopped maybe as Mr EngineMan said it is the coil, i have seen on the net about with a old good spark plug break the arm off and see if the spark will jump that, i will give that a try and see what happens. Thank you all for your help and tips and anyone have any outher ideas would be grateful.

Sorry i just noticed i have put this in the wrong place.

Hi all, took the hedge trimmer down to local garage and got them to test compression and it was only showing 50 i believe from what i have read that means its knackered, got it home pretty fed up and thought that it still felt ok on compression so gave it a tug (switch set to off) then put switch to on, no choke, no priming and it started up and ran no problem, used three quaters of a tank of fuel and it seams to be going fine. Only thing was it started up in the kitchen and the wife was not to happy. When i checked the spark arrestor it was not to bad but i think i will replace it anyway and may look into getting a set of piston rings for it.