OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines B&S 12.5hp v twin cylinder help, please.

welderman,

I would remove the cylinder head and check for carbon around the valves because it could be stopping the valves from closing properly causing all sorts of issues.

We do require more information as grumpy said like the model type and code of the engine and that way we can give you correct clearances for the valves etc.