FIRST OF ALL WHAT DO YOU CONSIDER HOT? TO CHECK YOUR FUEL SYSTEM FOR LEAKS TAKE OUT TANK AND FUEL TUBING PUT TANK UNDER WATER BUT KEEP VENT AND FEED SIDE ENDS OF TUBING OUT OF WATER SQUEZE CLOSED VENT END AND BLOW INTO OTHER IF YOU HAVE LEAK YOU WILL SEE BUBBLES COME OUT .AS FOR THE ENGINE IT IS MUCH EASIER TO JUST SEAL ENGINE I SEAL ALL MY MOTORS EVEN WHEN THEY ARE NEW.