MC2150 - What does the dashpot do?

[rgates]

What is this doohickey?

http://i43.tinypic.com/2m637rk.jpg
edit: not my carb, pulled an image from google images for reference.

MC2150 diagram says it is a "Throttle Solenoid Positioner (Solenoid Dashpot)". Wikipedia explains a dashpot as a "damper that limits motion via viscous friction".

Where it's positioned on my 2150, the throttle linkage doesn't make contact with the dashpot until the throttle is nearly closed. I don't see how it can do much dampening when the linkage doesn't contact the dashpot until it's reach the end of it's travel range?

What does the dashpot do? Is it emissions related? :confused:

[Ristow]

idle solenoid. when working properly,when the key is turned on,it gets power and extends the piston to open the throttle to it's preset amount,which sets the idle speed. when the key is turned off it de-energizes,fully closing the throttle,to prevent run-on.

i remove them,and use the curb idle screw on the carb body,just like the older carbs did. a properly tuned engine won't diesel (run-on) so they're not really needed.


that one has a dashpot on it as well. the dashpot gently returns an engine to idle when the throttle is rapidly closed. it prevents stalling under load which can happen on a lean burning engine such as late emissions controlled carb'd engines.

[rgates]

Right on. So it's two different devices in one. The diaphragm-shaped dashpot that prevents stalling under load, and the solenoid with the rubber boot on it that extends to set idle speed.

Think I'll remove it for now. Can always throw it back on if needed. Doesn't sound like it will be.

Thanks for the learnin'.