Tuning help with HPI RS4 3 EVO

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RCNT Member
RC Driving Style
Hey guys i just bought a rs4 was running good until i stripped it down to clean it. I think i need to adjust the throttle servo. Carb is open too much so its going full throttle at idle. I tried pulling the screw from the servo and moving it to 1mm but it keeps going back whenever i put it in reverse. Any help is appreciated!


RCNT Champion
RC Driving Style
Bashing, Racing
I'm sure we all been here ok there's what u do unfold the servo horn turn on the transmitter then the car it's will then move all servos to center idle position put the horn back on at desired setting and screw it in .... If this don't work you may have the servo in the wrong way

---------- Post added at 6:57 AM ---------- Previous post was at 6:55 AM ----------

If that all isn't the case adjust the idle screw till the carb opening is about a credit cards width open and tune from there for desired effect

Nitro Nerd

Gone - bye bye.
RC Driving Style
Does the carb close when you 'brake'? Trying to understand 'keeps going back whenever I put it in reverse'. You are sure you did not accidentally switch the throttle setting to reverse mode? If not, remove the horn, set the trim to 0/neutral. Put the ball link on the carb ball, and then when you put your servo horn back on, ensure that you do so in a manner that prevents the carb from opening any. Be sure not to put it on and then trim it in....instead if you have to use the trim do so with the horn off, then put it on. Hopefully this makes sense.