I came across a good review of Young Sun 43 yachts by TalkoftheDock. My SY Tiki was a ketch rigged centre cockpit, twin cabin version of the Young Sun 43 built for a US owner. She survived a de-masting in Hurricane Hugo Sept 1989 and is now cutter rigged and with some ballast removed weighs a mere 20 tonnes – a lot lighter that the original specs. Her revamped rig was designed so she sailed like a dream in the lightest of winds (view the superb results of our light wind Parachute trials) She also has a refurbished Perkins 4.236 engine located under the centre cockpit and accessed between the galley and workstations.
When researching her history it was difficult to sort through all the conflicting posts of information and the review has certainly shed some light and helped clarify a few things.

The first Young Suns were designed by Ron Amy, built in 1978 in Taiwan and sold into both the US and Australian markets under different names. It was available as either a center cockpit cutter or pilothouse cutter and there were four interior layouts available. The little sister was the popular Perry designed Young Sun 35.
In the US market the design morphed into similar versions built at the Formosa Boat Builders yard. She had at least three cousins – the Formosa 44, Spindrift 43 and later, a Hampton 43 that was built in China.
via Young Sun 43 Review.