Revs burst up, when idling. why?

[Nitro-the-way-to-go]

I have my brothers 1/8th Sacker X-2, he can't get it to go.

So i decided to take it for a week to fix, i can get it running, but when i let off the brake, it idles nicely for a few seconds, then the revs just burst up until i brake, Then the revs drop.The throttle stays in the idle position when this happens.

I'm not too familiar with his buggy.

why? any help? any suggestions?

 

[Rolex]

Turn down the trim knob to the throttle, and adjust the idle screw with the brake applied.

 

[Nitro-the-way-to-go]

Cheers, i have done this, and the car is going fine.

Thanks for the help.
(How do i close this thread? lol)