Is it missing when you get on it? What eng, how long doing it, any new mods? I would suggest R&R ing the plugs even though they look OK they CAN be deceptive. 100 psi is too high, I'm assuming cold on startup, how long has it been that high, how much when hot at idle and at cruise. Pressure reg might be sticky/stuck. I'd put a racing filter on there just to make sure it didn't burst which 100 psi is capable of doing just that(not a for certain that it would) but for the price of one of those filters I'd want the peace of mind & if it's a BB 1st take out the reg/spring out of the pump & see what you see.