I have a DLE 55. It ran fine for some 4 flights but what happens now is that when I push the throttle to anywhere more than 50% the engine goes into a smooth consistent 2 seconds cycle of going to max RPM and the dropping to mid RPM(i dont know what this phenomena is called). I have fiddled all I could with the low and high needles but no use. Can it be the ignition system or something else? Thankx in advance

Things to check, throttle servo, clogged internal carb screen, air leaks, ignition battery and plugged/pinched vent line.

whats a vent line?

That is the second line on the tank to bring air in as the fuel is being depleated.

gr8 thankx i think u solved it, i have both the lines plugged

Winner winner chicken dinner.......LOL glad I could help.

Shawn beat me to it. That dumbass married to my wife fired up his Brison and all kinds of strange things were going on. Then he discovered he left the plug in the vent line. Removing the plug cured the problems.