I feel justified at this point in saying that I have "resurrected" the 1972 Honda CB350F I have been working on on and off for a couple of years now. First, because the starter circuit rusted out (precipitating a growing need to replace all the handlebar controls on the bike as soon as I can), I needed to as a temporary measure wire in a new starter switch. To do this, I bypassed the wiring that goes up through the handlebars to the starter switch there, and wired in my own substitute zip-tied to the frame of the bike. Then, in a move that I rightfully criticize others for doing, I wired the other side of the starter solenoid directly to the negative terminal of the battery. That's fine temporarily, but I will replace all that wiring when I replace the handlebar controls. For a temporary fix, it works fine and shouldn't present any problems in the meantime. I fabricated a small connector on the end of a 10ga solid copper wire strung directly on top of the airbox, which is about to become extra storage space (for tools or whatever) since I'm putting velocity stacks on the intakes to replace the air cleaner assembly.
So, after some further adjustment and some priming of the fuel system with an oral syringe full of gasoline ("No, Mr. Pharmacist, I do not have a prescription I would like to fill this syringe with."), I got the bike to start, reach operating temperature, and idle for several minutes very loudly. I can't even begin to describe in this blog posting the level of hootin' and hollerin' that then ensued as I proceeded to rev the engine until it backfired a couple of times to clear it. Suffice it to say I was very animated.After several minutes of idle, I stopped the engine to check the spark plug condition. For those who don't work on cars or bikes, spark plugs are your window into the deep interior of your engine. They protrude into the actual combustion chamber in the cylinder, and are the origin of the many explosions inside the engine. The deposits that collect on them are both similar to the deposits left on the sides of the cylinder itself, and are extremely helpful and indicative of the state of the engine. I could see from the state of the number 2 and 3 plugs that those two cylinders were getting fuel delivered to them (the plugs smelled like gasoline) but weren't igniting strongly. When I held the plugs up against the engine block and turned the engine, with the plug still connected to its ignition wire, I saw a quick bright-orange spark. What I really wanted to see there was a hot blue spark. The tip of the plug was also nearly completely free of any carbon deposits. You don't want your plugs to be caked over with soot, but you definitely do want to see them become blackened a little. There should be a nice, even dusting of char on the whole surface of the plug, sort of like toasted bread, stopping at the threads (which should be completely unexposed). NGK has a very helpful pictorial guide for reading the condition of spark plugs. So, I started troubleshooting the rest of the ignition system, eventually coming to the ignition points and condensers. These were in original condition and probably hadn't been looked at ever in the entire life of the bike, but both condensers were worn out. The ignition points themselves looked like they were in okay shape but without replacing the condensers first I can't really speak to their condition. I adjusted their gap using a feeler gauge and left the panel open for when I get the new condensers.
I just now got a set of finer feeler gauges specifically for the adjustment of valve clearances on Honda motorcycles (damnable Honda with their ridiculously tight tolerances has those clearances at a nearly-impossible-to-get-exactly-right 0.002"). So once I get that done this afternoon I should be rid of the slight ticking/tapping noise the idle makes. After I make the rest of these adjustments and adjust the timing advance and everything, I think I can reasonably call this bike in better condition than any other time other than when it rolled off the factory line in Japan. More updates to come. Keep your throttle steady and ride straight, space cadets.