Really late in my response but hopefully it will help someone searching.
If the change switch is missing, both the wires that went to it need to be grounded. If not, the electric start will not work and the reverse rev limiter will engage all the time.
This, check the change switch in the back of the transmission.
Green/red wire grounded will allow you to start it but will have a rev limiter and cant go past 1/4 throttle.
Gray wire grounded will release that limiter but wont allow you to start it.
I could have those wires reversed but I will verify it tonight and post up.
I tried grounding both wires and it was still limited, grounding just the one wire gave me full power. I'm in the process of running a 3 pole switch to the front for easy starting.