I'be been working on draw-thu turbo bikes for 20+ years now and have develped this upgrade/service kit for the ATP wastegates as fitted to all ATP turbo kits.

Kawasaki Z650, Z1, Z900, Z1000, Z1R-TC, Honda CB750, CBX1000, Suzuki GS750, GS1000, Yamaha XS1100, they all have the same square constructed wastegate.

The original spring in the ATP wastegate is far too strong at 80lbs rating and is very hard to control for repeated and accurate blow-off, especially at pressures below 20psi.  The spring in the new service kit is much better at 40lbs rating, and has been tested repeatedly for years and ensures repeated and accurate blow-off.

If you're not convinced you need this, I hope what haeppened to me never happens to you.  Many years ago on one of my bikes the ATP wastegate failed to blow-off (dump), this resulted in pushing close on 45psi into my motor and sandwiching all four pistons!

This complete service kit (Pic 1) contains everything you need to service and upgrade your ATP wastegate.  The kit contains a new 40lb spring (Pic.2, item 3) a new 5mm ball (Pic.2, item 1)and two new gasket joints (Pic.2, item 2), plus complete detailed instructions (Pic 4) on how to fit it.