What is the model number of the mower? Emporers don't have a blade clutch!
If you DO have a BBC (Blade Brake Clutch) on a Mountfield mower, it's not an engine part. It will be a Warner Electric (company name - it's NOT an electric clutch), sold through Mountfield.
phil_saunders(a)bigfoot.com
Phil Saunders, September 2009