New carb, won’t rev.

[cricketchaser]

So I had to replace the carb on my 15hp Nissan. It ran great before I put the new carb on (long story why I had to change the carb, unrelated to carb). Now, it will not rev past 2k rpms. It starts just fine, and runs like it is supposed to. Then, it just starts acting very unhappy. To re start it I have to floor it. What’s going on? The carb is brand new.

 

[cricketchaser]

By the way, it’s a 4 stroke.

 

[pvanv]

You did not mention model.
Sounds rich. Check for the check ball for the accelerator pump. Make sure you are not over full of oil.