Hi Don, it's definitely a vibration/balance problem, but with all you've done so far you would think that it would be getting better ie. flywheel and blade disc...there must be something that we are missing tho for the life of me I can't think what would cause this handle to vibrate so violently. Don, please keep us posted, mate.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl