Check the intermediate plug running to the R/R ..... I found mine to be severely
corroded ......... some people find theirs flat out fried.

Then

Check Starter relay solenoid and connections to it (next most likely issue)

29 bucks on Ebay to replace

After that wires to ignition switch.

Also remember some new batteries can
have a bad cell ! , maybe get it load tested at your
local auto store

 

http://www.electrosport.com/technica...ng-diagram.pdf

You might find this helpfull.