Marty Howard wrote:
Chassis is VERY stiff (two 8" main tube rails plus a full cage). I suspect slop in the motor mounts though. One thing I have noticed is the rear trans mount seems to untorque itself afer a weekend or two.
I don't think it's driver position since the seat is very stiff and there is a lot of support (kirkey Pro) and lots of beltage. But that is really hard to judge.
The question I didn't ask is how close does the shifter get to any sheet metal or other structure before any theoretically possible movement? If there more clearance to everything than any conceivable movement could use up that isn't the problem.

If it is close, use some putty, etc. and look for witness marks. I'm assuming the trans is a modern "shifter goes directly into the trans" rather than the older rube goldberg shifter linkage outside the trans.
Another question might be whether something is preventing full clutch disengagement in one direction versus the other.
Also, what does the trans mount bolt to (sheet metal versus strong tube)? I'm assuming the motor mounts are on the big frame rails. Could there be some "local" sheet metal distortion that then puts a torque on the trans housing resulting in a bind inside the trans or clutch or???
Is there any chance that since you are being pushed into the left rear area of the seat in a right turn that either your leg or your shifter arm is having to "stretch" to either get the clutch fully depressed or the shifter all the way to the far right of the shift pattern?