# Stihl 36 weed trimmer



## G.MAN (Jul 8, 2012)

*WILL NOT START.HAS GOOD SPARK COMING OUT OF PLUG.REPLACED PLUG ANYWAY.COMPRESSION IS 90 PSI AND AFTER PUTTING OIL IN CYLINDER THE COMPRESSION WENT UP TO 120 AFTER PULLING STARTER 10 TIMES.SPRAYED CARB CLEANER IN CYLINDER AND DOES NOTHING BUT CRANK, NOT EVEN A POP OR CRACK AS IF IT TRYED TO START.DISCONNECTED MUFFLER AND STILL NO DIFFERENCE.THE PISTON AND DOES NOT LOOKED SCORED.I AM TRYING TO DIAGNOSE THE PROBLEM RIGHT THE FIRST TIME. ANY THOUGHTS APPRECIATED.:wave:*


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## geogrubb (Jul 28, 2006)

G.MAN said:


> *WILL NOT START.HAS GOOD SPARK COMING OUT OF PLUG.REPLACED PLUG ANYWAY.COMPRESSION IS 90 PSI AND AFTER PUTTING OIL IN CYLINDER THE COMPRESSION WENT UP TO 120 AFTER PULLING STARTER 10 TIMES.SPRAYED CARB CLEANER IN CYLINDER AND DOES NOTHING BUT CRANK, NOT EVEN A POP OR CRACK AS IF IT TRYED TO START.DISCONNECTED MUFFLER AND STILL NO DIFFERENCE.THE PISTON AND DOES NOT LOOKED SCORED.I AM TRYING TO DIAGNOSE THE PROBLEM RIGHT THE FIRST TIME. ANY THOUGHTS APPRECIATED.:wave:*


I have a FS85 and a FS46 that are hardheaded at times, so something to try, remove the spark plug, now, nochoke no throttle, no nothing, crank it over 15-20 times, now put about a teaspoon of fuel in the cylinder, re install the spark plug, prime the bulb enough times to make sure fuel is available to the carb, now no choke, no throttle just crank it over easy, no need to get in a hurry trying to pull your head off, just keep cranking slowly and after a while it will pop, then it will pop,pop then putt, putt, don't give it any throttle or you start over. Most weed eaters you put them on choke and crank until they start not on a finikey Stihl they will never start. Have a good one. Geo


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## usmcgrunt (Sep 16, 2007)

G.MAN,I haven't worked on very many Stihl's,but it seems like you could have a piston ring that is stuck from carbon build up.The compression should be higher than 90 psi and adding oil to the cylinder seems to indicate some leakage around the ring.Pull the muffler and using a plastic knife or something similar,try pushing on the piston ring to see if it will move in it's groove.( that phrase would make a good rap song title) If it is stuck,you could try bringing the piston up to TDC and add a little Seafoam or Techron to dissolve the carbon over night,or,pull the cylinder and "carefully" work the ring free.

The fuel lines could also be a problem if there are any cracks allowing air to enter.Here is a link to fuel line replacement.





Hope this helps.Paulr44 is the resident Stihl (amongst other talents) expert and hopefuly he will stop by with a comment.


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## Don L (Jul 14, 2012)

I would remove the spark plug,flip the trimmer upside down,choke off,throttle wide open and pull the starter rope five or six times,blast the spark plug with carb cleaner,reinstall and hold the throttle open with choke open while starting.
If it dose'nt start check to be sure it is'nt flooded by removing the spark plug and cranking it upside down too see if any fuel comes out the spark plug hole.
If not I would check the key which is cast into the flywheel,however the key is so small it's easy to mistake a good flywheel for a defective one so note the position of the flywheel in relation to the crankshaft before removing.
In the ten years I worked in a Stihl dealership I could'nt count the number of times I've unflooded one of these.


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