Mercury 15hp 2 stroke quits after about 30-60 min of use, then hard to start

I had a previous problem that it would only run on one cylinder which I fixed with a new coil. It ran great for about 1 hour and then it started cutting out and only run at 1/2 speed, then for about 5 sec it ran at full speed. This went on for about 20 min, then it ran great.

I thought bad fuel, so I went into a marina and they dumped the fuel, and I put in all new fuel and oil. Started on first pull, ran great for about 45 min, then cutout and quit. It was hard to start.

I let it sit for a few hours and it started on first full. Ran great for about 45 min, then cutout and quit. It was hard to start. So, I readjusted the low speed jet. Ran great for about 30 min, then cutout and quit. It was hard to start. Let it sit for a few hours and starts on first pull. Repeated a few more times.

Each time the fuel bowl/filter was full and squeeze bulb was hard.

Prior to this I:
1. Rebuilt the carburetor
2. Put in new switch box
3. put in new coil
4. put in new fuel
5. put in new spark plugs

It is like something heats up and then shorts out?? How would I test for this?

Can someone give the the resistance readings for the stator wires? My serial number is OG553602.

Any ideas?

Thanks
Tom