New Answer: I'm working on our water heater pilot problem and here is what I found out.
I removed the pilot assembly (Tube and all) from the unit and while air blowing through the tube I found out that the end with the orifice on it slips off. Mine was dirty and slightly plunged. You can not get anything through the orifice because it is to small. I tried to use the smallest Route Canal file (Very Very small) and it would not fit. I just blew it out for a while and could see daylight through it.
I fired it up without the orifice on the end and a large flame came out. I put the unit back together with the orifice attached and all is working fine now.
One last note: I carry a small propane
blow torch to use in emergency situations should the hot water heater refuse to light