Check your valve adjustment. I usually back the adjusters off at least 1/4 turn to create noticeable valve lash at the rocker arm with both valves closed if I suspect that valve lash is affecting a compression reading. Also try squirting a little oil into the cylinder before checking the compression.

You did remember to install the new rings, right? LOL! I did a post-mortem on a failed engine rebuild once, and discovered somebody had forgotten to install one oil ring. The guy who assembled that engine came down with a case of Budweiser Fever on a regular basis!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!