I would assume its a power torque engine??
Got good compression??
Got spark???
Got fuel??
Fixing it is a process of elimination.
This is generally how i do it.
Got good compression??
Hows it feel when you sping the blade plate by hand (plug lead off)
Pull the starter off and grab a torch and look up the bore.
Should be very few scratches etc.
If its not looking the best, Pull the muffler off and look at the piston. hows it look?? All scratched and horrid and its no good. If its a bit so so,
Pull the inlet off and look at the piston on that side.
Then theres crankcase compression.
Spinning the motor, are the bearings grumbly? Sloppy?? Bottom seal OK, is the top of the flywheel wet or oily?
The starter seal o-ring, is it OK?
Is the decompressor OK? It can be replaced with an old spark plug for testing.
Got spark???
Test with the plug out resting against the motor.
Test with plug out and throttle in the off and start and flat out positions. (always do this after removing/fitting a carb)
Test without the plug. Watch not to zap yourself.
Does the ignition module have a good earth??
Is the plug a known good plug?? Just because its new does not mean its good. Not common but not impossible.
Got fuel??
Spark plug wet?
When the starter was off was it wet in the crankcase.
You rebuilt the carb, if its dry,
Is the fuel tap blocked, do you get a good flow out the fuel line?
Is the jet blocked?
Needle and float need to be matched so they work in that 'primer face'. Sometimes with a short needle the float will stop moving (hit internally) before the needle seals up. And the opposite where the needle takes up before the float has moved up enough.
Fuel height in the carb is directly related to mixture.
