I have a Titan IO-375 (360 with high compression pistons) on my RV-7 with 155 hours on a new engine. About 15 hours ago, I started experiencing start problems. Cold start technique: throttle cracked, Mix rich, boost pump on for 3 seconds, Mix cut off, engage starter, advance Mix slowly. Now it just takes several attempts before it finally starts, usually resulting in a flooded engine after so many attempts. Hot starts are difficult but NOW cold starts are more troublesome. Do you think my coupler went bad at 155 hours on the mags? Mag checks on runup are fine.