I have had fuel leaks also. My fuel is red and easy to identify in the bilge. I have put small wraps of oil diaper material around fittings and secure them with a cable tie.Slow or random leaks are easy to find. The smallest nick on a JIC face fitting is enough to cause a leak. I avoid NPT threads if possible in favor of o-ring sealing or JIC type fittings. I use loctite 567 as pipe dope on all NPT threads. Last time I was stopped by the USCG the first thing they did was to look in the bilge for fuel--- there is a check on their form for just that. It can take a while to find intermittent leaks. Edmond Badham COSMO Wilmington, NC