Sunl SL250-22 Cooling Issue

[Crash4723]

So I bought this 2008 SL250-22 from a retired guy that only put 55 miles on it in the last 5 years. I drove it home and it blew the head gasket. Little did I know the PDI was never done and it still had that crappy stuff in the coolant. Took it to a local shop and they replaced the head gasket and got it running again. When I got it home I drained all the coolant and flushed it with hot water for about 30 minutes. Re-filled it with coolant, burping it over and over, leaning it to one side, then to the other, ride for 2 miles, refill, let it cool down, refill, etc..

My commute to work is about 4 miles and the scoot does great. Temp gets to a little less than half the dial and stays there. My commute to school is about 15 miles and the scoot does not so good. The temp rises above the 1/2 mark and then races to the extreme hot mark. At that point it doesn't matter if I idle it down or if I cruise at 20 or 30 or 40 or 50, etc. The temp stays hot.

Anyone else have a similar issue? This weekend I am going to take her apart and pull the radiator and make sure she is clean inside and out, pull the thermostat and make sure there isn't plastic or debris stuck, etc.

Can I remove the thermostat all together? I live in California, don't really have any cold weather. Will removing the thermostat all together cause the coolant to rush through the radiator too fast without having a chance to exchange the heat? I am not too worried about reaching optimal operating temp, but I am wayyyyy more worried about it getting too hot.

Any advice helps. Thanks in advance!!!