if it runs awesome on the track with no syptoms/sounds of too lean on bottom end whilst racing and comes in after 20~30 minute race singing daisy your all good. almost all the sirios at worlds were doing this, the factory guys motors just sounded too damn lean in comparison but they were making some serious power with no signs of fading during the qualifying etc granted they had andrea working on the tuning driver to there motors and who would know the motors better.