Hello all. I am currently turning a 73' CB450 into a cafe racer. I've run into a few snags along the way. Rebuilt a starter, replaced clutch springs and caps. Motorcycle runs, but I discovered that one cylinder compression tests at 0 psi. So, I checked the valves to make sure they were all at least moving and they are. I can tell that the exhauust valve looks like it's oil fouled. It's not just carbon, it's greazzy. My next thing to check is the valve clearance and then on to removing the head and checking for more serious problems. 2 questions.... 1, am I missing something that I should check before I actually tear into the engine. 2. Any way to get a downloadable factory service manual online. I couldn't find a used one. Thanks.