ok i been having broblems with my cat i had the whole top end rebuilt and the carbs cleaned and jetted has great compression and will start and run but it idles high and can not be adjusted down by the idle screw the real problem is when it under power it will run fine for a minute or two then it stalls and will not start back for a while ( does anyone know what the sytems could be or know what is happening ) ive spent so much time and money tring to get it back to normal im just lost for ansers