I have a 36 ford with a 59-ab in it. The motor idles great but when trying to drive it pops and has no power. I cleaned the carb and that helped some. But it starts and idles great I can reeve it up and it sounds good just trying to move it won’t get out of its own way. Am I missing something simple. What are some things that I should check and try. This is my first flat head
Developing a miss under load sounds to me like an electrical problem. Check the spark (plugs, leads and coil).
I know I have spark since it runs but how do I check it to see about under a load. It has a new coil on it
Is the new coil correct? A lot of guys mix up 6 volt/12 volt. Did the problem appear after the coil change??? Check the ignition leads as in this link. https://www.championautoparts.com/Technical/Tech-Tips/Defective-Spark-Plug-Wires.html#:~:text=Use the digital multimeter, set,12,000 ohms-per-foot.
It seems all that is left is the condenser and the accelerator pump. The latter can be checked by removing the air cleaner, actuating the throttle linkage, and watching down the carb throat for a healthy stream. Condensers? These days, you can get two or three in a row that are marginal out of the box. If you haven't already, try another. If you want to be sure, there are sources for reliable condensers. One that comes to mind is the Vertex magneto unit. If possible, you should take a compression test, if only to see where you are with overall engine condition.
So, you cleaned the carburetor, it ran better. How about a full, real rebuild of the carburetor? Or did you clean crud from the bowl?
Ok, next steps are ignition leads and plugs. Test the leads with a multimeter as in my link in post #6. Test the plugs with a multimeter as in this link: https://west-equip.com/blog/post/how-to-test-your-spark-plugs Remember the old saying.... "Most carb problems end up being electrical".
Lots of easy things to check before getting into the harder stuff. Better to sneak up on these sort of problems, one step at a time.
As far as I know, there is no difference in condenser for 12v or 6v. Well they shouldn't be causing your problem. Did the problem start when it was converted to 12 volts, or has it developed out of nowhere? Maybe check and replace or reset the points??? It is easy to test and check the ignition system first without starting to spend any money on stuff. Also check the fuel filter and the air cleaner. If none of this fixes the problem you may then have to dive into the fuel system side of things.
Yes, and it could very well end up being a fuel delivery problem, but it is really easy to check and eliminate other possible causes at zero cost before spending to rebuilding a carb and possibly finding out it has made no difference...