I have a 73 CL175 K7 that will not idle. Here is what I have already addressed: points timing is spot on, all potential vacuum leak areas have been sealed on the carbs, carbs have been synced, idle circuits on both carbs are clean with compressed air three times, slides are completely bottomed out at idle stage, choke mechanism works as it should, jets are stock and needles, floats are set at stock 21mm. I can start the bike by opening the throttle up but I have to hold the throttle above 2k rpm, anything below this will kill the bike, it will not run without holding the throttle open. I have great spark, all mechanism are in good working order. Somebody suggested I disconnect the throttle cables completely in case the slides are not bottoming out, tried that, bike will not start at all in this condition. Absolutely aggravating. Any ideas, thoughts here? Thanks in advance!