note front forks are dt200 ie no rubber mounted bushes..
UN-related to your vibes issue and more so just out of interest -
How did you fit the DT200 front forks are they the same diameter as the original ones and did you use the DT200 or the original triple clamps? I have a DT400C and the original forks are in very poor shape so to make it useable I have fitted a combination of XT/AG200 tripple clamps and forks and maintained the original front wheel but due to the XT triple clamps being less of a V configuration they clash with the original tank so I have had to fit a different one for the time being.
Here's how it looks at the moment
Am interested to hear more about yours. Do you have any pics?
Cheers Troy