Homelite ranger 33cc chainsaw will not start. replaced spark plug, no luck. next thought was to drain fuel & refill with fresh, but fuel isn't old & i doubt if it has water in it. any other suggestions?

Did you check for spark when the plug was out? It should be blue and snappy. If not, you need to expose the flywheel assembly by removing the left case cover, then remove the stop switch wire from the ignition module. If now sparks, check the stop switch and connecting wire for grounding. If still no spark, replace the ignition module. Use a thin businees card for a gap gauge--turn the magnets under the module, insert the card into the gaps, then loosen the mounting screws and let the module stick to the magnets. Tighten the screws and rotate the flywheel to remove the card, then turn the flywheel one full rotation and check that the gap doesn't close up at any point. If the original test had good spark, then pour some fuel mix into the plug hole and attempt start--if you get several pops, then check the fuel system. Start with checking the fuel filter which will commonly plug up over time and check the fuel lines for decay or damage. Does the primer button pull fuel into it when pumped several times? Go to: http://www.drystacked.com for a 12 page article on Walbro brand carburetor theory and trouble shooting. Note carefully the items within the lower chamber as they are critical to proper running. Hope this helps!