Ive also got a corniche with 41bs in if you pm me your email address I'll send you manuals for the engines but if you look on the keypart or volspec sites all service parts are listed there
Hi my 2, 41a units run circa 30 psi idle and circa 60 psi at revs (hot) ,In my princess these gauges are electric and there accuracy is on only generally indicative and not to accurate,,,if in doubt get a temporary mechanical gauge used for checking. my units have 1100 hrs and regularly serviced from new,,and have no problems apart from usual cold start smoke,do you have any other reasons for doubting your engines ?