Spark, Compression, Fuel but no fire

[priorshane]

Hi all... I actually have a McCulloch Super Mac 26 string trimmer which has sat for 5 years. It has good spark, 92psi of cold compression and I poured a little fuel into the cylinder and still no fire or splutter... Any suggestions? Thanks

 

[Boobala]

Remove the muffler/exhaust, then see if it will fire .

 

[priorshane]

Boobala, Removed the muffler, still no fire...

 

[Boobala]

OK you have compression, try a NEW plug ( be sure its a proper 2cycle model, ) get an in line spark tester

see examples, .....


I prefer these neon models as they are easier to see in daylight conditions, but it's your call . install the tester,
then put a small amount of mixed fuel ( starting fluid washes down the cylinder walls and can lead to scoring ) into the carburetor throat while holding the throttle WIDE-OPEN ,
CONTINUE to hold throttle wide open try starting engine watching tester to verify spark. If engine sputters
you have a carb. issue, if no sputter no spark, it's ignition issue, also see this link ,

http://www.ereplacementparts.com/article/7348/How_to_Diagnose_Two_CycleTwo_Stroke_Engines.html