Runs Lean at High End, or Lack of Power
Look at the plugs. Tan, or brown is good. White, or near white is too lean.
- Check float level
- Test the fuel pump. It might be on the weak side.
- If the engine has been sitting for months then the gas has probably coated the inside of the carburetor with varnish restricting flow.
- Jet size – You need to think about this. Jets just don’t change that fast. Now if you just replaced the carburetor, then the jets and/or metering rods may need to be changed. If you have been driving with this carburetor, then changing jet size is just covering up some other problem.
- If you think you need to change jets, or metering rods, try the metering rod 1st. They are easy to change (be sure to put a rag down the carb throat), and the carburetor can be mounted on the car. Measure the existing rod and then pick a rod that has a smaller power size.
- The carburetor may just be dirty with restricted passages. A cleaning/rebuilding would be in order.