Grounding A Portable Generator In A Truck Need Help Grounding My Yamaha Portable Generator?

Need help grounding my Yamaha portable generator? - grounding a portable generator in a truck

I tried to call Yamaha and they were useless.

The guide says:
Connect the ground cable to the machine ground terminal and connect the end of the ground electrode buried in soil. "

The machine now has a green / yellow (earth and neutral, I believe), the engine is connected and bolted the other end to the chassis. This is the thread that is said in the manual and no other. The problem is the ground terminal, which is behind the control box. They seem to be that the G / S and my son joined the mass electrode (earth) ground. However, these devices are also more than seven inches and remove, if the G / Y wire frame that will not come, even if I remove the engine. I'm not sure what the hell am I supposed to do for this market. Should I the G / Y wire and prepare the ground wire electrode into the ground (earth), the terminal behind the control area? He is a Yamaha EF2600, brand new right of the field.