I just replaced the engine in my atc 185 .when I start it ,it automatically goes to wide open throttle. You can squeze the throttle but the engine speed does not change. All i did was swap the carb off old engine ,ive got no idea whats wrong.

 

It sounds to me as if the "slide" for the throttle is in wrong thus acting as if it is at full throttle. I would remove the throttle cable from the carb. and then turn the "slide" 180 degrees until it drops fully into the carb. That is the only thing I can think it could be.

 

What he said, or possibly your cable is kinked, is there a bunch or slop in the throttle thumb piece? Does it feel correct? Did you adjust cable after installation?

 

There are two slots in the slide, a idle adjustment, which is wider and shorter than the guide, which is thin and goes all the way up the slide, line up the adjustor with the adjustment slot on the slide, and as super golfer said it should slide all the way down, with only a few MM of clearance at the bottom, the push throttle to inspect that the slide is moving correctly. If that still doesn't work, post back

 

Thanks guys , the slide was it. I didn't pull it out when I replace the motor my son did so I didn't see how it came out . Thanks again Doug I