RE: 250° F - is that too hot?
I use the venom temp monitor on my DA-100. I actually have two, one for each cylinder. They are about $18 off ebay maybe cheaper. I lengthen the wires on mine and ran the temp displays inside the fuse for easy access. I then route the thermocouple to the highest fin closest to the spark plug (on mine, its on the back side of the head) then I snug it tight against the cylinder. It records max/min temps and current. Works great as I can see what type of temp I hit after I hover, then do a long upline.
Hope this helps.