G-11 intermittant non-response

[Gudog]

I have an older Yamaha G-11 Gas Utility Cart with a new battery. The Cart runs well (normally) with my son having dressed it up a bit with some paint, decals and electrical gadgets. We have recently had a problem (2 times) where the cart simply appears to be dead. Specifically, we ran the cart for 20-30 minutes with no problems and then parked in on a slight uphill grade. When we came back two hours later it would not even hint at starting. Pushing the throttle produced no response. The headlights and gadgets worked fine. When we put it in reverse the reverse warning signal came on for 2-3 seconds and then faded out. (Under working conditions it continues to sound as long as it is in reverse.) We had a four wheeler tow us 200 feet to our camper. When we arrived we tried the cart again and it started right up and ran like a champ. We ran the cart again for another 10-15 minutes with no problem and while doing so pulled over for a passing vehicle (ironically once again on a slight incline) and stopped to let the vehicle pass. When I went back to the gas, dead silence again. The reverse again produced the same 2-3 second fade out alert sound and all electric gadgets still worked. This time I had a four wheeler push us and after 15 feet or so I hit the gas. The cart stated right up as normal and ran like a champ again. We drove back to the trailer and loaded up. We have driven around our yard a couple of times since with no problems. I have since learned that this happened to my son one time in the fall of 2012 also (Not sure if happened on a grade?). The cart is run two weekends per year. October 1st weekend for the grass drags and Labor Day weekend for Crandon Offroad. It sits in the garage the other 360 days. Grass drags are in two weeks and I am hoping that this problem can be resolved before then. Thats as specific as I can be. Does anyone have a suggestion....we are not mechanics!
Thanks

Jim

[smallblock450sl]

Might help to read the "sticky" above..."so your Yami won't turn over". With a volt meter, do the tests. You may find the battery drops below 10 volts (can still run lites), but not activate the solenoid or turn over the starter/generator. Good luck. PS, some pictures of the grass drags would be cool

[Honorstick]

Maybe a dead spot on your generator/starter, just a thought.