New member here and I know this is an old thread. I acquired an old 92 Briggs and stratton 5 Hp Industrial / commercial 132232-4036-02 attached to a pressure washer. It was in extremely bad shape. Probably should have been thrown away, but I figured I would try and bring it back to life. Im running into the same problem now after restoring it, the engine surges bad. If I apply about 1/2 choke it runs perfect. RPMs are steady at 3600. I also thought I did a thorough cleaning on the carb, removing both welsh plugs and really cleaning the fixed jet and all the orifices I could see. But no change. I even tried a different cheap carb. Similar problem with surging but if Choke is applied the engine stalls out. I’ve taken the carb out again to clean it.. now waiting on all the seals to come in. I figured it is an air leak somewhere but trying to find it Has not been easy. I don’t have a service manual, but found somethings online . what is the normal compression on a 5 hp? I have 75#. it starts first pull, i just don’t know what the “range” should be.