From the manual:
Up to 6 seconds of pre-heat (in cold weather), then press start.
This means:
Confirm transmission to neutral
Confirm throttle to idle
Up to 6 seconds of pre-heat
Press button ... it starts easily every time.
In my experience, the pre-heat is not required above 20 degrees C, but use it if you find it doesn't start instantly.
DO NOT add throttle (Yanmar GM and YM series need 2/3 to full throttle, Yanmar JH and Beta must not have any throttle advance).
I do find them a little harder to bleed the fuel system than Yanmars. So now, I don't change both the primary and secondary filters at the same time. I do one one day, the other another day and thus minimal fuel bleeding is required.
Don't idle for more than 5 minutes. Start it, give it a minute to confirm consitent water flow, then go. Idling for long time is really hard on the engine and clogs the exhaust elbow. Run it at 75-80% RPM. Running lower is a false savings. Ensure you are propped to achieve max RPM to max RPM +50... If you can't reach rated RPM, your prop or tranny gearing are off and your engine will suffer in the long term. That's 3600-3650 RPM for your Beta 20 at max throttle, in calm seas, with a clean hull and clean prop, with your normal load onboard (people, fuel, water, food, etc...). Cruising RPM should be 2700-2900 RPM. If you can't achieve 3600-3650, your local prop shop may be able to slightly reduce the pitch without replacing the prop.
If you have any questions or concerns, call Gartside. Great engines, easy to service as everything is up front, especially if you opt for the optional oil change pump. I wouldn't hesitate to install another. Exceptional support in Canada. Parts are cheap and available everywhere (Kubota). Best of all, no computer required to service it!
One important consideration if you previously had a Yanmar, is that the engine raw water thru hull may have to go up in size. The Beta requires at least 19mm ID hose (3/4" ID). Your Yanmar may have had 1/2" hose thru-hull.
Gartside sells a maintenance kit that includes all the filters, belt, etc... which is a great value, all tucked away in a small tool box.