Soft Clutch Spring, 1 piece (OEM), lower manual force required than 500 series, needed 6x

We have successfully installed the 400cc series springs in 500cc series engines and were delighted with a clutch that requires significantly less manual force. Even though we didn't notice any clutch slipping in our tests, it could theoretically occur under full load.

The SR400 from 2014 onwards only has 23 hp, which is why the clutch springs are weaker there.