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Rougher83

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Discussion starter · #1 ·
Problem-After using trimmer for approx. 20 to 30 minutes it dies and will not restart. Let it set for a while and cool down, then restarts fine but will only run for another 20 to 30 minutes. Had taken to dealer for repair, and their diagnosis was carbon build up in the muffler which they cleaned along with carb. Picked it up to use yesterday and the same problem is occurring. Any help or insight would be greatly appreciated, so that I might help stear them in the right direction when I take it back. Thanks.
 
Rougher83 said:
Problem-After using trimmer for approx. 20 to 30 minutes it dies and will not restart. Let it set for a while and cool down, then restarts fine but will only run for another 20 to 30 minutes. Had taken to dealer for repair, and their diagnosis was carbon build up in the muffler which they cleaned along with carb. Picked it up to use yesterday and the same problem is occurring. Any help or insight would be greatly appreciated, so that I might help stear them in the right direction when I take it back. Thanks.
had the same problem a week or so ago. changed the spk plug and nothing. cut the wire and about 1/4inch and redid it. same thing. Take the whole unit off the fly wheel (spark plug unit) and replace it. Cost me 37+tax. This is your problem.
 
I have found that some of the Stihl line of products run alot better and less overheating of the eng, if you use Premium Gas in the mix instead of Regular. I have tested this on 2 of my pieces, and the one with Reg def runs rough after about 15 min of continuous use, where as the one with Prem mix, ran great...yes its more expensive but if it saves me trips to the shop and saves my equiptment I will do it for now....not sure if this is 100% true for what your talking about here, but just what I have found out.
 
Your ignition coil is bad. If this is IIRC a 2002 or later model year then it is under lifetime warranty and stihl will replace for free. If they dont warranty it then replace yourself.

Remove orange shroud from top of engine.
Locate the spark plug lead and follow back to ignition coil which will be just above the flywheel.
Unbolt and remove the ignition coil, if you have new one then skip this step.
Take ignition coil to dealer and get a replacement, usually easier since you will have the P/N from the old one.
Install new ignition coil by first rotating flywheel until the magnets are on top then place new ignition coil in its place and thread in the screws until snug then back off 1/8th a turn. Take a business card and insert between the flywheel and ignition coil pickup to set the airgap, tighten down screw(do this on each side)
Reinstall orange cover, connect spark plug lead and voila! Start the trimmer and you are back in business.
 
lawnmaniac883 said:
Your ignition coil is bad. If this is IIRC a 2002 or later model year then it is under lifetime warranty and stihl will replace for free. If they dont warranty it then replace yourself.

Remove orange shroud from top of engine.
Locate the spark plug lead and follow back to ignition coil which will be just above the flywheel.
Unbolt and remove the ignition coil, if you have new one then skip this step.
Take ignition coil to dealer and get a replacement, usually easier since you will have the P/N from the old one.
Install new ignition coil by first rotating flywheel until the magnets are on top then place new ignition coil in its place and thread in the screws until snug then back off 1/8th a turn. Take a business card and insert between the flywheel and ignition coil pickup to set the airgap, tighten down screw(do this on each side)
Reinstall orange cover, connect spark plug lead and voila! Start the trimmer and you are back in business.
After you tighten screws, then REMOVE business card.:laugh: :laugh:
 
Using a feeler guage (not a business card), what is the gap? It must be 0.010 or 0.012, right?

I replaced my coil earlier this season (FS85 trimmer), and set the gap about 0.010. The motor seems to start and run fine, but am I out of spec?
 
Discussion starter · #13 ·
Thanks for all of the information/help. After consulting with the dealer(mechanic) he too believes it is the coil that is the problem. The model is a FS80R which I have had for just under a year. I also have the FS80 model which I believe has been in service for nearly 3 years and not one problem with it. The FS80R however I have had in the shop 3 times now for various problems. Not sure if my next purchase shouldn't be either a Jonh Deere or Echo...we'll see. Thanks again fellow LCO's.
 
Rougher83 said:
Thanks for all of the information/help. After consulting with the dealer(mechanic) he too believes it is the coil that is the problem. The model is a FS80R which I have had for just under a year. I also have the FS80 model which I believe has been in service for nearly 3 years and not one problem with it. The FS80R however I have had in the shop 3 times now for various problems. Not sure if my next purchase shouldn't be either a Jonh Deere or Echo...we'll see. Thanks again fellow LCO's.
Unfortunately these new models on many brands seem less reliable. I was noticing that we are still running two Stihl 75 or 85 that are over 5 years old and have had minimal problems.
 
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