Do you have a fork brace?  Reducing binding due to fork flexing is a big help.

It might be time for new, low-sticktion fork seals and wipers, and top quality fork oil.

It would be good to call Ricor Racing Shocks, Tel: 888-425-1333, about their Intiminator motion sensing fork damping valves.  $150 promotional price, plus a quart of 5 wt. fork oil needed.  Who knows the inside diameter of our forks?

I do not have a fork brace.  I don't have a Corbin seat, a wider higher windscreen, good bags, a VM carb, or a large number of other things I would like to have.  Perhaps I will some day.

In the meantime, the additional weight helped immensely.  I imagine that the suspension behavior, especially the front end, is quite influenced by weight, thus heavier riders might not suffer the same chatter I have.

The term "sticktion" is useful.  I have never heard of low-sticktion fork seals.  I didn't know and still don't know what a "wiper" is.  I put in what seemed to be expensive fork oil.  

I presumed the chatter was from binding from the machines spindly forks coupled with a long front end.  

I notice Race Tech has some materials for the 650.  But not low stiction seals & wipers.  I have not pulled out and replaced such things.

Perhaps spraying teflon lube between the seal and wiper would be effective.

I was under the impression that the fork brace was the ticket, so finding out there are many more things to spend money on seems quite disheartening.  Any particular brand or source suggested?

I kept thinking more weight would help!
Thanks for the info.

Dont know why I havent tried it yet....except I just have gotten my fork/tool bag!
So now I'll try it...and add 5+ lbs of tools