Whats the difference between the 1990 550SX Piston port CDI vs. the 1993 550SX Reed CDI

I notice that the 1990 cdi has the hookups for external rev limiter and the 1993 does not(assumed to be internal)

The reason I ask is that I have a 1993 550SX Reed engine that came with stock CDI, I was having issues with the ski and swapped the 1990 CDI into it. This was not the issue. It was a fuel line that was the issue...

I currently have the 1990 cdi in their with the rev limiter not hooked up.... I was wondering if this is better or if I should put the stock CDI back in it.....

Also anyone know what the rev limits at on the 1993 cdi vs the 1990 cdi with and with the rev limiter hooked up???

Any other differences between the two....

Thanks in advance,

Picture of the 1993 CDI:
2013-09-05 00.02.22.jpg