Demon carb question, umbrella check valve

[latamud]

I was wondering, if the umbrella check valve that is installed with the accelerator pump and diaphragm was broken could this cause a lean condition at high rpms or anytime the secondaries were open?
I've been trouble shooting my tuning problem and think I found it.

I was going to swap jets on my secondaries and when cleaning the bowl out I noticed I couldn't see the nipple on the check valve sticking through the hole. With the bowl in my hands I pressed the accelerator pump lever and fuel shot back into the inside of the bowl through the spot where the check valve nipple would be. I just want to know if 'm correct in thinking this. Thank you for any input.

Bart

 

[D.Hearne]

It would do the opposite. It's there to keep the fuel from being drawn into the throttle bores while the pump's not being used.

 

[Max Power]

It would do the opposite. It's there to keep the fuel from being drawn into the throttle bores while the pump's not being used.

I disagree. It is there to prevent the accelerator pump squirt from going back into the bowl where the fuel came from and out through the nozzles instead. A one way check valve, so to speak. Like the old check ball.

These things deteriorate with some of todays fuels, btw.

 

[D.Hearne]

You're correct there, I was forgeting the check rod under the nozzle in the bores.