mazdatweaker
+1y
To answer the questions. . .
1. Do a compression test. Dry and wet. That will tell you if the engine is worn out.
If the compression is low, very little power will be generated. . .Less than these anemic motors produce under the best of circumstances.
2. It is really likely, from looking at your pictures, that the mixture control solenoid as part of your carburetor is not / has not been working for some time. . .and the previous owner tried to "fix" the sluggishness caused by its non-operation.
3. It is really likely, that if the MCS has NOT been working. . .that excess fuel has been washing oil off the cylinder walls for an extended period, leading to ring wear. A weber will not fix anything and will be a waste of time and money until the underlying wornoutness is fixed.
4. Your fuel filter may be located near the fuel tank (under the truck). And if it is full of trash, it will cause problems.