Rich/ Lean mixture Question

What is the diffence between a rich and lean mixture i know they have to do with to much gas or to much air are viesversa. My F-head has no air cleaner and the choke is stuck open and have a none orig fuel pump that pumps to much gas. p.s it backfires and sometimes doesn't idle good.

 

You've probably got bigger problems than just carb tuning. First step is to rebuild the carb and replace the gaskets to seal up vac leaks, and rebuild the distributor and set initial timing.

There is some good rich/lean reading in this thread:
http://www.earlycj5.com/forums/showthread.php?t=51842

And how to tell if your efforts are successful:
http://www.earlycj5.com/forums/showthread.php?t=52317

 

Put an air cleaner back on that thing. Thats the 1st thing!!! Rich mixture will cause it to pop thru the exhaust when you back off the throttle. The spark plugs will also be black and sooty. It is better to have to rich of a mixture than to lean of one. The back firing may be caused from to rich of a mixture and the fuel is burning in the exhaust system instead of in the engine.

 

Thanks guys i don't know the condtion of the gaskets and i need to ''Make" a air filter.