well i just got my new dtx .18 for my evader a couple of days and broke it in word for word from the instructions. Break in went well and I didnt have any problems but now im having some trouble fine tuning it. Off the line it has good accel. but seems to make a bubbling sound(kinda like bogging but not as noticeable) as it begins to accelerate, but this stops once it gets a few rpms under its belt. And the when it gets to full rpms it bogs down and will occasionally gets little power bursts(air bubbles?). My first idea was that the engine was too rich but im getting way past the manufactures settings. The engine temps are around 220-230. I would have to say the top speed when its at full throttle is 25-30 which is much slower than what it should be. I am unsure of what i should do to solve this problem. Ive tuned engines before so i got the basics down. Any help would be appreciated

Have you tried to set the adjustment needles at factory standard? Try it and run two or three tanks like that. Everything should settle to normal. Make sure everything is operating normally after the runs. Most engine problems come from trying to adjust the engine too much. The engine can't get used to the settings because it keeps changing.

Yea at factory settings seem way too rich and it bogs down at high rpms. Ive tried leaning it out and it still bogs down at high rpms. Ive tried richening it and it doesnt even get to the high rpms. I dont know what to do

I am experiencing a similar problem with my Nitro RS4 RTR 3. I think the piston sleeve may be damaged. When I run the engine lean, it seems to work ok. How lean is Duratrax's lean setting? I run mine very close to 1/4 turn on the primary needle. I am pretty new to nitro and the RS4 has only one adjustment needle. I think, maybe the engine is too dirty at the air intake areas. Make sure they're all clean: the air filter, carburator, etc. That's all I can say. Sorry I can't be of more help.