Toro wheel horse 16-38 xl surging and won’t go away

[courtneysg3 0]

Hello my name is Sean and I just bought a toro wheel horse 16-38 xl that keeps constantly surging I put a brand new aftermarket carburetor and a brand new aftermarket air filter, put a brand new oil filter, and even gave it a fresh oil change, but nothing is working to stop the surging. The engine is a Briggs and Stratton Q28q777-6190-E1 and the engine is from 1999 I am strongly suspecting the governor spring is bad. The previous owner who sold it to me messed around with the machine so he might have damaged the governor spring I ordered a new one because it was stretched out not horribly but enough to cause it to surge. I am not sure if the surging is normal or not any suggestions on how to fix it besides replacing the engine would be much appreciated. I hope that my toro wheel horse 16-38 xl is acceptable and not too new for this forum

[953 nut 54,644]

Surging is generally an indication of an inconsistent fuel/air ratio, A crack in the fuel hose or fuel filter could cause this.

[D_Mac 8,531]

When replacing the carb, were new gaskets installed ? Could be sucking air there. Also try running it with the gas cap off. Maybe the cap isn't vented properly.

[courtneysg3 0]

Yes but the fuel filter I believe is new I couldn't find any cracks in it the fuel line looks a bit thicker than a normal Briggs and Stratton fuel line, however I could not find any leaks on the fuel filter or line I will have to look at the fuel filter closer and make sure the previous owner didn't put it on baxkwards. The air filter I replaced is also new I had a friend test it with the cap off but there wasn't much of a difference 

[courtneysg3 0]

Oh and I put new gaskets on as well.

[D_Mac 8,531]

Fresh gas ? Make sure no water in tank or stale fuel. Drain the tank and bowl and start with fresh fuel.  Also could just be the carb.

 We all have had issues with aftermarket carbs.