Originally Posted by david s poole

there are two very small screen filters that protect the govenor,and if the inlet is blocked the gov will not allow valve body to shift up.you will need to remove the valve body and then the separator plate[with small valve body].on the topside of plate there are four screws holding the small valve body with a strange shaped plate.remove those and small valve body comes off and you now have access to small screen filters.if this doesn't prove to be problem then i would suspect valve body.