Suzuki 2 Strokes

Is there any Suzuki data that confirms what the max pressure a T500 & GT550 oil pump can deliver? I know what the crack pressures are for the check valves, however what is the max pressure capability of these oil pumps? Thanks

At the risk of sounding flippant, the max pressure those pumps can reach is the crack pressure and that's about all they need to reach to push oil into the motor. It has been way too many years since I studied fluid dynamics for me to work out what the theoretical max might be if feeding into a closed line. Logic suggests the burst pressure of the line. Fluid is basically not compressible, so a plunger pump pressure has to be limited to the mechanical strength of the components or the amount that can leak and cause bleed down of pressure.

In the real world, I don't think it's relevant as long as it exceeds crack pressure and crankcase pressure which could be be up to 20 psi

Its a positive displacement pump. The max pressure the pump is capable of would depend on internal pump clearances.

Suzuki did pretty conservative engineering back in the day. They might have had a requirement that a blocked line would not cause a pump or an oil line failure. Or they might have not worried about it because a blocked line would cause bigger problems in the engine.

My understanding is the crack pressure of the check valves is around 4.3 psi, however what would happen if you fitted new balls and springs in the check valves and the crack pressure was higher with the new springs at around 5-6 psi or even slightly higher, would theses oil pumps be able to handle the higher crack pressure?

I can't guarantee it, but I'd be surprised if that was a problem. Are you fitting springs from Germany or something else? You can replace the check valves with Kawasaki items.