Ok, let me start with it is a 1978 cb750k with the pd42b carbs, stock air filter box and new emgo air filter,I just put on a mac 4into 1 with the baffle Part number (801-1301). I have pulled the carbs and went through them way too many times to say..lol I cleaned them and got the accelerator pump working great, cleaned the main jet and the pilot jet (with a high e .010 guitar string) and did the clear tube method of checking floats. which was a fiasco because number 1 bowl kept having a drip every 4 seconds which had me pulling the bowl off and checking the float height 10 times. arrgh until I found the hairline crack in the bowl from most likely me turning the drain screw in too far. I guess I went just past "a half turn before it breaks" method or trying to get it to stop leaking. The bike starts with choke and runs (its been 40 degrees out) and after warming up it idles fine at about 1700 rpm without choke, I synched the carbs because it wasn't synched after the rebuild. I may mention that the a/f screws were out almost 2 1/2 turns out before. I now have them set at 1 1/2 .I pulled the spark plugs and Number 1 plug is carboned up a good bit, number 2 is less carboned and 3 looks just slightly carboned and number 4 actually looks quite passible. It has only run in the shed where I have been working on it this winter, pretty much at idle to 3500 rpm with revving for about 45 minutes. 20 minutes to do the synchronizing and then 20 minutes for getting the exhaust up to temp to re-torque exhaust claps.it was never under load as far as riding so Is this normal and what should I look at to get all the plugs looking the same.
As a side note I want to thank this forum for helping me with my "journey with this bike, I have made a jig for my carbs, picked up a lawn blower gas tank which have helped with synching making life easier, I have learned allot from reading through here.
