Honda 2000 start issue

My Honda 2000 which I have had for over 5 years has developed a start issue when cold and high elevation 7000 ft. it has always ran great up there. When it's level starts and runs for like 20 seconds then shuts off like I hit the off switch, wait 10 seconds starts right up, this goes on for about 10 starts then it will keep running, no load, have tried turning off eco switch, does not work; for whatever reason I tilted it about 30 degrees off level away from starter side and it will keep running on the 1st pull, hold it that way until it warms up and it's fine but it I set it back to level again before it warms up it shuts off again. Oil level is full, gas full, fuel pump is new, any ideas?