I made an extension on my manifold with rubber car hose to clear frame below the seat...it is about 6 " in length.. what are the pros and cons of this...My engine is a 48 cc Flying Horse with a RT carb.....
No cons aside from possible problems from poor mounting and air leaks.
Gasoline also damages some hose so be sure it's gasoline rated hose.
Usually helps low end and throttle response a bit.
Experiment with different lengths to tune to your needs.