78 kz1000 running problems

recently my father decided to give me his 78 kz1000. the bike has not be ridden for pretty much the past 5-6 years and sat at my uncles house for that time. he cleaned out the carbs and got everything back up and running. i was told that the only thing i needed was to get it synchronized, i brought it to one of the guys at my work who has worked on bikes and carbs for a while. he went through the carbs and found a couple things off, floats unlevel and a couple plugged ports. he cleaned everything reassembled and synchronized the carbs. everything seemed to run great on my first trip around the block, after i came back i let it sit for a little then decided to go on a little longer trip. about halfway to my destination i didn't think i was going to make it, with the bike at higher rpms the bike seems ok, but once i accelerate from a stop or switch gears the bike bogs down and a couple of times it stalled out when i tried to start off from a start. it seems that it only happens when the bike is hot, i've tried everything i could think of except adjusting the carbs, the charging system didn't seem to be working, fixed that, a couple of the spark plug boots were cracked, fixed those but nothing seems to help. the bike is a 78 kz1000 which i believe was bored out to a 1200, it has a vance and hines 4 to 1 exhaust and mikuni vm33 smoothbore carbs on it. i don't believe anything else has been changed on it any help would be greatly appreciated

it sounds like its time to check your valve clearences, my bike was doing that to me until i adjusted my valves. Hope that helps.

Have you checked the plugs to see if it is running lean? Also do the coil mod and do a compression check.

After the carb work, was a new in-line fuel filter installed before the test drive? If not, a fresh supply of crud may have entered the carbs.

Your friend at work found a couple unplugged ports?
And he plugged them for you right?
There's a possibility that those unplugged ports are actually vents, and they don't need to be plugged. They do look just like vacuum ports, but originally they had vent hoses running down past your swingarm. If they're plugged, your bike won't run right.

thanks for all the information, i got to spend some time looking at it today and found that the guy at work adjusted the jet needle, i put it back to the point where it was and everything seems to be working good, so hopefully i can get a couple days of decent riding in before it gets cold up here