bogs at low rpm

[JHPSTANG]

I've got a rebuilt 1100 carb on my old 200, and just had my mechanic adjust the timing and the carb. I just replaced the cylinder head and had the head resurfaced. I put on new headers as well. Now it seems to bog down/hesitate at low rpms. it will sometimes lurch if I give it too much gas in 1st from a stop. It runs fine at higher rpms and idles fine. I've read a little, but not sure where to start. I guess I need to get a vacuum gauge and a timing light (don't have either) and see for myself what's going on. Any suggestions where to start? Thanks!

 

[MustangSix]

1. accelerator pump
2. more timing

 

[JHPSTANG]

Ok, so I checked the accelerator pump by pushing the throttle, and I'm getting a good squirt of gas in the carb. But then I noticed that I have a leak at the base of the carb spacer on the intake manifold. I did notice there was no gasket there when I reassembled after the head gasket. Could this cause a vacuum leak that would cause these symptoms? There is definitely some fuel coming out there with then engine off when I give it gas.

 

[rbohm]

8) yes a vacuum leak will cause the very problem you have.

 

[JHPSTANG]

So the vac leak between the carb spacer and intake manifold was pretty bad. I just put in a new gasket(there was none!), and even just idling in the garage (it's raining outside) it sounds like a different engine. I can't wait to drive it when the rain stops! Thanks for the help!

 

[rbohm]

8)