Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Both cylinders firing on the engine? Have you ran a cylinder balance test? How is the compression? Is the exhaust open and not restricted?
OK, Seems like the fule has no place to go.
Compression is ok. So let's see what leaving bypass hose open does.
Have you swapped the carbs?
How hard would it be to swap exhaust?
Ok, let me know.
It has to do with the vacuum in the cylinder. The fuel has no place to go.
My understaniding from you ,was you swapped carbs both ways and carb worked fine on the other unit!
Now that makes no sense!
OK, have a nice day!