Hpi bullet wont idle and is cutting out when braking, and isn't revving high. I bought it new in match

[Stelad69]

 And since i trying to tune it after breaking it in it hasn't ran properly any help and advice would be greatly appreciated 

[Stephen shr]

How old is the fuel ? And spark plug 

Edited June 24, 2021 by Stephen shr

[Nitroholic]

Sounds to me like your idle is not properl;y set. If this is the c ase, when you brake, you close off hte carb inlet completely killing hte motor. It would also explain why it won;t idle.

 

Not only that, if it isn;t set correctly, it will cause issues in tuning in general.

 

To check it:

 

Switch on servos, but do NOT start the engine. Remove the air filter so you can see into the carb. At idle, you want to see a gap of 1mm at the widest point between the edge of the carb inlet and the slider.  Then apply brake, and see if the gap closes up.

Correclty set throttle linkage and idle stop screw will have the 1mm gap at idle, and it will not change when you brake.