T maxx 3.3 full throttle after 30 seconds idle

[Wesmills24]

I got a t maxx 3.3 and it starts up and idles fine but after about 30 seconds it starts screaming wide open throttle. Never touched the gas or anything and can clearly see the carb is shut but yet revs so high it seems like it could blow up. If I press the gas the servo works fine and carb opens and closes fine but continues to be full throttle. If I kill the engine and restart it it's fine for another 30 seconds or so. I've tried cleaning the carb just incase just to have the same issue. Rather new to nitro. Any help is appreciated

 

[tntpoof]

sounds like the carb needs to be rebuilt....

 

[cbaker65]

I got a t maxx 3.3 and it starts up and idles fine but after about 30 seconds it starts screaming wide open throttle. Never touched the gas or anything and can clearly see the carb is shut but yet revs so high it seems like it could blow up. If I press the gas the servo works fine and carb opens and closes fine but continues to be full throttle. If I kill the engine and restart it it's fine for another 30 seconds or so. I've tried cleaning the carb just incase just to have the same issue. Rather new to nitro. Any help is appreciated

It sounds like it is leaning out on its own ,make sure that the fuel tank is clean ,an the header & muffler is not leaking ,
an also ,make sure that the pressure tube is not restricted or plugged!

 

[Wesmills24]

It sounds like it is leaning out on its own ,make sure that the fuel tank is clean ,an the header & muffler is not leaking ,
an also ,make sure that the pressure tube is not restricted or plugged!

Would this also cause it to smoke white?

 

[cbaker65]

Would this also cause it to smoke white?

I don't think so ,in fact ,it is good to see a trail of smoke coming out!

Maybe ,you have a massive air leak ,causing it to rev high!...
Because ,if there is some smoke ,then that does mean that it is getting fuel ,unless that is a fog rolling off from a
hot engine meeting the cold air!....lol

An air leak might cause that issue ,the leak can be at the carb throat or the head ,make sure that the head screws
are tight ,sometimes they work loose ,I've ran across that before ,an use some Copper sensor safe gasket sealer
on the carb to seal it!.....

 

[olds97_lss]

Also check that the carb is fully seated and the cinch bolt is tight. In an RTR, it's usually tight out of the box, but I'm not sure if the engine was new/used/messed with, so check that too. If it's not fully seated, it will allow for a nasty air leak at the carb neck.

Loosen the carb cinch, gently twist the carb back and forth while pushing it down, hold it down with your thumb to put pressure on the o-rings, then tighten the cinch.