help stihl 660 no spark?

[timfish]

Ok ya'll im new here and i have a problem--i bought a two year old stihl 660, when i bought it, i put some gas mix in it and she ran like a BEAST!! i then probbed over the saw, checking plug etc, all looked grreat-i bought it,,one week later i emptied the tank and put new gas, bar oil in there to make sure there was no problem-now she dont run, new plug,
no fire? but the saw is two years old with less than 20 hours on it, good compression/clean fuel filter/etc
QUESTION-
before i buy a new coil (120.00) could there be a loose wire? could the plug wire and the spark plug boot have come loose?
Ideas/HELP-- please

 

[Tree94]

first things first, make sure you didn't flood it....

 

[timfish]

no, i checked the plug, no fuel on it, its clean, when i turned it over the other day (after i checked the air filter emptied fuel cell) she 'burped but nothing else after that...ideas?

 

[ironman_gq]

Check for spark first of all. Beyond that it's more than likely a carb problem. I've had the needles get stuck over a 2 week period and I've had them run great one day and not start the next.

 

[Tree94]

obvious, I know, but make sure there is a gap on the new spark plug... you never know.....
maybe try putting the old spark plug back in and seeing if it starts?
retrace your steps, could be a bad spark plug.. unlikely but still possible..
if it started right up last week, id assume carb and coil are good unless you messed with em..

 

[blades]

Ditto on the bad plug- it happens and just maybe ya dropped it? or the wrench slipped and cracked the porcelain. Poor plugs have been showing up quite a bit more now days ( thanks Global MFG.) Switch is on I hope ( Seen that little detail a few to many times.) occasionally they go bad or the lead gets rubbed bare grounding out the coil.

 

[timfish]

im on my third plug--gapped .020, removed the coil, cleaned contacts replaced using index card as spacer--question though---the flywheel is not completely round, is slightly oblong- my GUESS its closer to the coil/magneto in relation to the upswing of the piston--if i am wrong please correct...