This is about the 1985 i just got.
seems to happen when i let off the throttle, at pretty much any speed.

Do they male "anti-speed" wobble units that i have seen on newer bikes for mine?

 

I'm sure you can find a steering damper for your ride, but if it does it every time I would guess it is caused by something else. check your whole front end for loose bolts, worn tires, bad rotors, bad bearings, fork alignment, anything that could possibly cause your problem before moving to the damper.

 

Steering head bearing by the sounds of it. If you have a shop manual for the bike I would torque the nut down to the proper spec and see if that helps. I think if it was a tire, rim or rotor it would do it all the time, BUT you never know.

 

hmm, not 100% sure yet. How are your tires? Do a quick check on your steering head bearings. (front brake on and rock the bike). Any noise or slop from the steering stem? Have you checked for leaking fork seals? (You should already have the bikes sag numbers set), but double check your fork damping adjustments.

If you are talking about steering damper then that would be the last thing to consider at this point.

 

Sorry, let me re-phrase that.
It does it when i remove one hand from the handle bars.
I had a bike guy look at it before i bought it, and he said all that stuff was good, but ill get a second opinion.

 

Removing a hand from the bar shouldnt effect it at all in the straights. Looks like there are some good suggestions, I'd still stay away from a steering damper until you get her buttoned down.

 

I have a wobble I can feel that I know is caused by the tire. I reduced rake and in turn trail when I raised the rear end by rotating the chain adjuster in the direction to do so and installed a 110/70 instead of a 110/80 to quicken turn in. With tire wear the front shakes a bit. It's mostly noticable as I speed up from about 20-50 mph or, of course, if I take my hands off the bars. It's not a problem since I know why it's there and it's not too bad.

I'd agree with a high speed wobble all the bearings should be checked out and possibly a steering damper added. The steep rake and shortish trail of a sportbike will make a wobble much sooner than any older standard or, for sure, any cruiser types.