Quote: I can't speak about "genuine SU's," I can only speak about the Hitachi's that i have on my GX engine, & i used them for many years without any hassle. They just need to have the oil level in the dampers checked periodicly, & every now & then i had a look at the adjustment screw that ensures that the two carbs open at the same time. Other than that, they received no attention.
In fact, when i finally wore the engine out, i rebuilt it, & re-installed the manifold & fired it up. It did another full service life without any repair, or major tune up on the carbs. It just shows that the Brits may have come up with a good design, but the Japanese made it work.