ORIGINAL: Bax
There are no parts diagrams and such for the O.S. pump system on the FS-120 Surpass III. If your engine has a leaking pump or regulator, then it needs to go into the service center. They are service-center-only parts, per O.S., and are not available for general sale.
For free I sure hope for the life of the engine...if a manufacturer builds a part and doesn't allow folks to buy parts...especially in a hobby industry they must disclose this upfront. Bad bad bad.