No, If you take out the sparkplug of the opposing cylinder to the cct your changing you can turn it over by hand and feel the compressionon every other revolution, then you can line up the TDC marks on compression stroke

This was a tip from a Honda mechanic.
After I changed it I took out both plugs and turned it over very slowly by hand just to double check

To anyone else out there If youre not confident don't do it Dels yer man for the job.
If anyone has a haynes manual rip the cct bit out cos its bollox, I remember following their procedure step by step on a Z900 years ago and bent the valves
Warren