Hi,
Im trying to fix my neighbour's Rover 375 Briggs and stratton mower.
The mower misfires and the revs dont go high too much.
If i manipulate the carby by finger it revs and revs high.
The springs look ok .
I have cleaned the carby and changed the diaphram spring and gaskets. Also have cleaned the flywheel , coil and set the gap at .20mm . I have a manual says between .15 - .25mm. No change.
Changed the spark plug to new and set the gap to .75mm.
The only thing that concerns me is that there is rust building up on the flywheel magnet face. The mower has excellent spark and great compression. Muffler is not plugged up and have decarbonised the piston and exhaust areas. I have changed the oil and fitted a new air filter.
Im stumped!! please help

Thanks