250cc keeps burning up race CDI boxes

[G-gaurd]

Hi
I got this coolster 250cc water cooled single seat dune buggy the stock CDI is A/C 6 pin box and works just fine but the RPM'S are limited and I've been trying to put a race CDI box on it so I can open it up and have a little more fun

So far every Race CDI box I install as soon as I turn the key to crank it over it burns the box and I do mean burn ..... electrical burned smell from the aluminum boxes and the epoxy plastic boxes start smoking and hissing

The wires are all hooked up correctly and grounded ..... even after the race box failures I plug in the original stock box and the motor starts right up . So far I've cooked around 5 different race boxes both A/C and one D/C

6 pin box
2 pin is A/C power and kill switch
4 pin is pulse wire ... coil wire and 2 ground wires

I'm totally baffled and I hope there is a way to run a race box

Thanks in advance for any and all assistance