I need gearing help!!!

[yzinger02]

Im running a 1518 1250 kv on 6s in a muggy and I cant seem to find the right gearing. I've tried 16,19, and 22 tooth pinions and the 16 was definitely too low and the 19 was too low so I tried the 22 and it was overgeared. I have a friend with a xerun 4274 motor in his FLM emaxx and that motor hardly ever gets over 120F and my 1518 is hitting 170F at times but mainly in the 160F range. Im running a MMM esc and it gets about 115F and my battery gets to about 130F. Please help!!!