bogging when warm

I'm hoping that this will sound familiar to someone, My 76 KZ750 was running great. One day I noticed that it seemed to bog out when it got warm and it ran rough, I changed the plugs and sprayed some carb cleaner into the carbs and rode it an hour to work, it ran great, coming home it also ran great. The next day I went out for about an hour and at first the idle was really high and didnt want to come down, gradually it did...after about a half hour it started to bog out again and I had to turn around and head home, the whole way it ran like that, rough, boggy... I'm guessing it's carbs but I havent a clue..anyone ???


1976 kz750 B twin

i had some of those same issues with a 1000...... my ignition timing was off and i had lots of air leaks through manifolds.....just something to take alook at if you havent already.

Rob

I looked at the mainfold and I don't think thats the problem rob, as for the timing I'll have to check that, but wouldn't that do it all the time then and not just when it was hot ? from reading other posts I've found I should check the volts at the coils, for leaks at the rubber boots, timing and then carb's float level etc (beyond me so it's shop time if the problems not obvious) does this make sense though, it's happened twice where the bike seems to sputter and bog after about an hour of riding when the bike seemed to run great, and I don't know if it's a coincidence but both times the bike sat in traffic for a while idling right before it happened, could heat be causing something to loosen or stretch that would either draw air or change the flow of gas to the carbs ?