I have a 20 hp Honda (gx629 v twin) that keeps cutting off around 10 min while running with a load. Motor will then start right up again and run for around a min and do the same thing over and over again. I doesn't matter if throttle is up or down. Any suggestions where to start?

I would check fuel solenoid in front of carburetor. I got tired of cleaning mine , so I removed it all, cut the wires, then screwed cap back on.

I went over that earlier in the season. It seems to be working fine. I had a fuel separator hooked up for a while when this first started. I unhooked it and ran the fuel directly from the tank and it seemed to stop. Now it is back at it. It seems to be a fuel problem. I wonder if it could be the fuel pump.

I spent the weekend working on a friends GT. He had the same issue and I had it too a couple years ago. Mine was the mechanical fuel pump. It would start up and run fine. Put a load on it and it would die. Start up get going and poof all of a sudden it would die. It pissed me off and I finally got on here and at the suggestion of others on this forum went with an electrical pump. I never looked back.

The facotry Mikuni pump is only rated at 3 foot head. Well where it sits in relation to the fuel tank you are already at or above 3 foot. Then I had to add in the 20 feet of line from the front deck fuel tank. You might consider checking the fuel pump.