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99 220 ,cleand and rebuilt carb ,new piston ,new packing ,decent cylinder lining 40:1 klotz benol. My problem is smoking. Any help would be greatly appreciated

First off, since I don't know your experience with two stroke motorcycles, they do smoke no matter what. If you are talking about excessive smoke then it can be a few things causing it. Float height, leaking jet block gasket, rich jetting, and/or leaking right crank seal are all possible causes.

"cleaned carb"
How did you clean it? Did you remove the jet block via tamper proof torx but on underside above float area, and replace the jet block gasket with a genuine Keihin from JD Jetting or Jets R Us?

Cleaning the carb with solvent without removing the jet block gasket usually further conpromises a 20-30 year old formed o-ring gasket. Also, using brass parts from aftermarket rebuild kits takes you from being close to correct on jetting backwards to unknown jetting territory. The needles are especially critical, as they hare a lot more precise and have a lot more critical dimensions than a fixed orifice in a jet.

You didn't state whether it was smoking prior to rebuild either.

Is it running good? Or very blubbery?

Does it consume gearbox oil without any major external leaks? That could mean right crank seal is bad.

What is the compression test reading?

Have you pulled the exhaust and inspected the piston through the exhaust port? What's it's condition?

There's a lot to weigh here before determining the cause if the smoking. And as was stated, 2-strokes will smoke more than 4 steokes, ESPECIALLY if left to idle for extended periods, and especially if they are not opened up and ridden hard once warmed up to 125° F or hotter.

Provide these details and we'll be able to better guide you onto a path of serious enjoyment of your fine bike!