Originally Posted by
1QwkSport2.5r
The throttle stop on the carburetor needs to be set so when the throttle is released or brakes engaged that the carb closes to the throttle stop instead of closing completely. You want to have the throttle stop set so the carb is open 0.5-0.7mm at idle. This setting must be adjusted in conjunction with the idle mixture.
Exactly. The addition of a return spring pulling the throttle body completely back to idle may be needed. When you apply the brake, its putting the throttle body in the true "IDLE" location. Check your trim if there is a return spring installed already. You may just need to trim the throttle so that its allowing the body to return to idle. Then adjust your idles screw to open the gap slightly. Good luck.