Hi all.
I have a 26cc DZY engine with an electric ignition.
the engine was ran (brake-in) for a half a galon on the ground and the needles were tuned and set to H-1.5t & L-1.25t.
the engine is mounted on a biplane.
i did the testflight on friday and everything went perfect... the engine worked great and the plane flew great.
on saturday, i went to the field, had two PERFECT flights with the engine... and then the problems started...
fueling up for the third flight, starting the engine, checking for WOT and the revs start to go up and down.
it seens the engine just cant ran at WOT.
just a reminder, the engine worked perfectly before.

after a hour of fiddling with the needles - no go.
at home - i took apart the carb and cleand it really good, there was some dirt in it , especialy in the little mesh filter in the fuel input.

put the engine back together, but the problem wasnt solved - it starts hard and just dont want to run at full (or even half) throttle.

the ignition is powerd by a 2 cell lipo battery with a voltage regulator (5V).
i tried using a fully charged 1000mAh nicad battery - no go.

there is no problems with the fuel lines, the engine gets the fuel directly from the tank (no fueling nipples on the way), the tank is well ventilated.

messing with the niddles just doesnt help...

the engine sounds like its starting to build up revs and then just quits and go back to idle ... and again, and again... all of that without even changing the throttle position.

I really dont know what to do, any help will be appriciated.

Thank you.
Raviv.