im running a odonell 99 plug in sav 25
http://www2.towerhobbies.com/cgi-bin...?&I=LXCKB4&P=0

probably should clean the carb, hi/lo needles and ports with carb cleaner. i think i set my needles 3 turns out and tuned from there.... temp gun helps i dont let mine get over 260...u got compression right? sounds like same problem i had and this was the fix....i dont think the last ring gets red on any plug....try it on your new one and compare. hope this helps these things scream