Kz550ltd carb woes

Hi guys, I’ve been lurking in this forum for a while, recently bought my KZ550LTD which had been in storage for a vast number of years 
anyway, a couple of months work got it back on the road but I do have a very slight issue.

my bike runs fine until the last 1/5 throttle, then it bogs down slightly
the plugs are showing a good burn.

one of the problems the bike had when I got it was a jammed ignition advance, which freed up quite easily…
but on investigation the main jets are 105’s instead of the 95’s I expected.
I wonder if the previous owner didn’t recognise the stuck advance and tried to compensate with a bigger main?
now…this is where it gets interesting.
The float bowl vent pipes are blocked off…and it runs beautifully like this.
if I unblock them it splutters a little and has no top end…

any advice?

Are your floats set correctly?

Return things to stock per the manual and see what you got. It's possible the previous owner modified several things to compensate for perceived problems or misdiagnosed problems.

There is a link to Tk22 carb website in my signature. It has some hints not covered I the manual.

Thanks for the advice guys,I changed the 105 jets for 95 and voila….normal service was resumed
simple case of over jetted