If only one cylinder has unusually high compression, it's often a sign of (1) carbon building in that cylinder, or (2) sticking valve.
To fix that in my TR, I removed the plug in that cylinder, dropped two tablespoons of Seafoam down into it, and used a rag to close the plug hole.
Let it sit for two (three?) days. Removed the rag, and saw there was no liquid in the cylinder (either drizzled down, or evaporated).
Then did another compression test. The psi was now nearly the same as the other three cylinders. Put the plug back in and all was well.
By the way, when you do a compression test, remove the plugs, remove the ignition coil center wire, block the throttle wide open (push the gas pedal to the floor), and use the starter to turn the crank the same number of times for each cylinder. That'll give you more reliable readings. Probably something else, but my brain has turned to jello again.
Tom M.