My weed whacker won't start... I put a new spark plug, checked for spark... ok... cleaned carb... ok... removed spark plug and placed gas in cylinder, replaced spark plug... nothing... even used starting fluid... If carb is bad, or gas is bad it should at least sputter a little with starting fluid / gas placed directly in cylinder.. . what else could it possibly be!

Worn out, causing low compression?

Worn out, causing low compression?
Relatively new unit... bought last fall... I even made sure to use it once a month all winter long... it ran great... I checked the piston... it moves freely... there's spark.. but won't even attempt to give up a little sputter... Had a similar problem with a tiller I have... if gone unused for too long the carb clogs up and sometimes the gas and oil separate... I always shake the fuel good before starting... but this has new gas... even with starting fluid placed directly into the chamber it won't even sputter... there's got to be something I am overlooking..?

If you've always run it with the correct oil/gas mix... then I agree it shouldn't be worn out.

You need ignition source at the right time (spark in this case) fuel and air in the right mixture. And compresion.

What's the spark look like... blue or yellow?

Spark seems to be blueish... but any spark should ignite gas in the chamber...

If its blueish you are good there. A weak yellow spark isn't always enough to do the job.

What exatly did you use to clean the carb out with? Not everythig will disolve varnish.

If its blueish you are good there. A weak yellow spark isn't always enough to do the job.

What exatly did you use to clean the carb out with? Not everythig will disolve varnish.
I used starting fluid... then gumout... followed by strarting fluid rinse.. always worked before...

Starting fluid isn't a really good solvent for gum and varnish... but the gumout is... I assume it's the carb cleaner Gumout because they make a variety of products not all of which are suitible.


Perhaps during the disassembly and cleaning and reasembly.. you didn't get the adjustment screws back to close what their original settings were. And if you didn't remove them for the cleaning... you missed some important parts that never got cleaned.