kz550 clutch problem....?

Bike in gear, clutch pulled, will still have plenty of drag unless the plates and disks are new. As they wear together, they tend to want to hold each other more. Sometimes you can fix that by scuffing up the plates with 220 grit, so they are not so shiny, but usually it's not a problem to warrant worrying about. As it gets hotter outside, and the oild gets thinner, they tend to want to stick together more.

If the bike sat for many years, and the plates are rusty, then you will notice they don't want to release all the way, nor will they want to grab all the way. Then it's time to take them out and sand them or replace them.

Be very careful with torquing the basket bolts. They like to snap off.

this may sound dumb but.... could i put seafoam in my crank case? would that clean the clutch?

No. I don't know if seafoam is meant to go into crankcases, but I certainly wouldn't do it. It's not really a matter of dirt. The plates are just polished together.

I think you will know whether it's a problem or not after you ride it. I wouldn't do anything with the clutch until then. It may need nothing.

+ 1 on the be careful about torquing the clutch basket bolts. The torque spec is in in-lb, not ft-lb....found that out the hard way.

Sounds like the clutch plates are stuck together too tight. Either physically pull plates apart from each other with clutch cover off or work throttle in top gear riding with clutch pulled in. Stuck clutches can be a pain in the azz.