accelerator pump

[416expowerman]

when i first start my quad up. if i give it gas wide open it sounds like it wants to shut off. someone told me it was somekind of accelerator pump. is this true???

[Old Head]

This is not a bash and no offense but reving the motor like that with no load on it is bad for the motor.

[wilkin250r]

The accelerator pump is inside the carburetor, and it only activates when you "stab" the throttle (open it very quickly).


The accelerator pump is kinda like a one-time shot, it doesn't stay "ON". It's not like a fuel pump.

There is a very small bowl on the side of the carburetor, and that bowl has two outlets. When you push the throttle, it squeezes the top of that bowl with a rubber diaphram, and it squeezes all the fuel out of it.

When you push the throttle slowly, all the fuel in that little bowl gets pushed through a large opening into the main float bowl, which really does nothing at all. When you let off the throttle, it fills back up.

When you push the throttle really fast, it pushes fuel through BOTH openings. Most of the fuel returns to the float bowl, but a small part of it gets pushed through a small opening right under the carburetor slide. This squirts a small stream of fuel directly into your intake.

The reason is that when you open the throttle really quickly, your mixture gets very lean for a second or so. Lean enough to bog and possibly kill the motor. So the accelerator pump adds a little extra fuel right at this time to improve throttle response and performance.



If your motor wants to die right when you stab the throttle, it might be your accelerator pump. But if you are HOLDING the throttle open, and your motor wants to die, then it's obviously NOT the accelerator pump. It's only activated for about half a second when you stab the throttle.

[2004exrider]

Where would we be without Wilkin :blah: . I always learn something new, or more than i knew whenever he leaves his big posts lol.

Jimmy

[Rip_Tear]

You might just need to let your quad warm up a bit before you start reving it hard... another possiblity is if the choke is on it might be too lean when reving it up.

[300ex mxracer]

if u do it right after you start it up it will do that

[416expowerman]

i was just curious on what it did ,thank you for your help