I have changed the coils, pulser, CDI box. Clean the carbs. But I still can not go faster then 55. I have power all the way to 50. But I top out at 55. Specs say I should do 100. I weigh 230 so I should do 80 or 85. It is a 6 speed transmission.

What does it do at that speed? If the engine just revs real high, it's your clutch. If it doesn't have power to go faster.......well........we would need more details.

It has no power. It doesn't rev up. Runs smooth no jerking. No spit and spuders. Just no power There. It quick through the first 4 gears but once I get to 50 no power. My throttle is all the way open.

Had the same issue with an old kawasaki I had. As soon as I threw out the Carby and replaced it with an aftermarket mikuni I never had the problem again?
Not saying this is the problem but just sayin.
Before I threw the old carby out I had it cleaned and restored and no fix problem

Thank you any other idea's

Check to make sure your slides are opening completely and equally. Have you done a compression test?

I've weighed 230-250# while riding my GSs and I hit 110 mph indicated on the 97 with a big Plexi 2 shield on it so I don't think your weight is the problem.  Wonder if you have something restricting top speed and power in general like the restrictor on bikes in UK and other places for beginners or if you just don't have the power to pull more than the 55 mph or so.  Have you tried downshifting a gear at 50-55 to see if it will go faster?  Compression test like Rich suggest is a good starting place to check it out.  If you just acquired that 81 GS450 check the gearing to see if it has standard number of sprocket teeth.

http://www.bikez.com/motorcycles/suzuki_gs_450_s_1981.php

Check the seals between the carbs & the intake pipe. Squirt a bit of WD-40 there while holding the throttle steady. If the engine revs, you have an air leak. If that's the case, try to tighten them down; you may get lucky.  If not you need to replace them. After 30 years the rubber hardens a bit. Also, check to see if they're cracked. If that doesn't do it, my money would be on partially clogged jets. Clean the carbs again, or replace the main jets.

Valve clearance. Had an 82 450L that was lethargic. Clearance too tight in Exhaust. She opened up after that.