Hello. I'm having trouble setting up my weber 48ida on my stock 12a. It will idle at about 1100rpm and then it just spikes randomly. I've tried adjusting the screws but I can only get it down to 1100rpm with it staying alive still.
Video link:
https://youtu.be/ZJBO4RGdddI
Specs:
Stock port 12a
Full straight pipe exhaust
185 fuel jets
185 air jets
F7 emulsion tubes
42mm chokes
200 needle and seat
70 idle jets

Thanks!
I have a video uploading right now showing the problem

 

I could be wrong, but I thought the 48 was too big for a stock port 12a? I'm running a 45dcoe, and I can get it to idle @ 850-950 and run it as a daily driver. Also, what's your FPR set at?

 

No you are correct ha-ha! But it's what I have lying around so it's worth a try for a bit more power! I believe my carter pump runs about 4-5 psi. I don't have a regulator.

 

I don't know that the pump is your spiking issue, but I had to add a regulator to my carter because my Weber (dco) would drip fuel into the throttle body due to over-pressure. The Weber prefers about 3psi and the Carter was putting out about 7. I would assume your ida would be similar.