Chinese BBD Knockoff...?

Well I went to his house last time put new plugs in and fired it up it was unusually loud. at some point he said "there no exhaust coming out of the right pipe" went and checked and then looked under the car, the right muffler was blown wide open I said "did you have a backfire...?" so I know he at least loaded the rightr bank up and had an explosion in the exhaust... like said hes condemning the engine but evidence points to a flooding condition...fouled plugs blown muffler etc.