So, I have been trying to troubleshoot this for the past month or so. I just finished up a rebuild on the carb. Followed all the posts that I could find. Removed all the stuff that doesn't matter. (including the choke, choke plate, altitude adjuster, vac box, ect) It has mech secondaries with the modified accleerator pump per the sterling post. That setup seems to work great!

The carb is getting nice levels of fuel in both bowls. (checked via a mirror on a stick) Also the transistion between primaries and the secondaries is very nice. The motor idles rock solid at 750, and I can adjust that up and down with no problems.

The problem is that it REFUSES to run nicely between 1k and 2k rpm. So school zones, taking off from lights ect is a HUGE PITA. It doesn't even want to really rev up past 2k unless I baby it. You have to be real careful and rev it up past 2k before you let out the clutch or it will die. I am wondering if the transistion between the idle circuit is the problem. NO clue what to check on though.

Thoughts? Ideas? If you can help me fix it, I have homebrew I can share.

 

Verify that you still have spark on the leading ignition, just to rule out an ignition issue (which this really does sound like). Also, check the timing while you're at it...

 

Hmm, I will try that. The only thing I changed was the carb, so thats why I Thought that was the issue. Time to put a new cap/rotor/wires on anyway.

 

If it's not ignition, the transition circuit comes to mind.