Reply To: Upgrading GT250R Suspension to GT650
400ML is usually max capacity but hyosung has updated the 650 forks 3 times! (Old , Newer , and 2020+ updates for their current LED GV650 models which borrow GT forks!)
So if you want to use 650 forks on your GT250 = Get the silver ones. This is up to 2008 as a safe mark. Around 2009-2012 different countries started getting black 650 forks with updated calipers.
So 2005-2008 GT650 should be fine 🙂