I have a SLA 110l that won't start. It will turn over yet won't fire up. I replaced battery and carb. I have good spark. Not sure what else to do.

 

Well if you have it, try using some starter fluid.

Also check compression.

 

if you can get it to start with starting fluid you may have a stuck air bubble in the fuel system. I ran into that with one of mine. I just took a extra pc of fuel like put on carb and held strait up and filled from a squirt bottle full of fuel.. Had to give it a slight blow to start the fuel though but never had issues since

 

has good compression would not start with starting fluid should what to do now?

 

did you hold the throttle wide open when you gave it a squirt of starting fluid? Try a squirt bottle of fuel. I have never had luck with starting fluid on some machines due to the angle you have to try to get the can to spray. Squirt bottle you can give a strait stream of fuel easily from a distance

 

if your compression is >95 psig, you have fuel in the float bowl with clean jets to deliver fuel(you verified fuel is present and spark plug is getting wet with gasoline?), you have spark, valves are set, air filter is clean so carb can breathe, then it should fire up. i wouldn't think timing would be off at this point. but try this, there is a phenomena that occurs in which you can test for spark outside of the jug/cylinder, reinstall the spark plug and spark dies. sometimes the fix is as simple as a $3 NGK spark plug.