Then I would get a temp gun and run the bike for 4-5 minutes. Just running without load and jetted correctly the cylinder and the head should stay between 185-205. If it's getting really hot you might be running really lean, but until you fix you exhaust leak you can't really jet the bike yet
OK I think your main problem is that your jet is a little rich. I'm at around 500 also with full exhaust, port job, and head re-chambering done and I run a 280. Is the bike bogging out at high rpms?
Your compression is little low. Should be around the 120 mark or higher. A new top end would most likely fix that. Exhaust leaks are horrible for long periods of time. It will make jetting eratic and the bike could potentially run lean, which in turn could ruin a top end. Your jet also seems a...
I've been getting my cylinder and head re-chambered and ported but when I went to put them back on, my piston was cracked. Does anyone know how this happens? I have around 30+ hours on the motor. it's a wiesco piston with wiesco crankshaft.