I responded to a Craigslist ad for a "Vintage Honda motorcycle" with an electrical problem and a title. The guy was moving and couldn't figure out the problem, so he was practically giving it away. I bought and paid for it sight unseen, and was blown away when I did see it.
Straight off of the pickup:
The gas tank is flawless:
Cleaned up a little:
I was told the bike ran great until this year, when all of a sudden "no power was getting from the battery to the engine" or something like that. I pulled out the battery, it was showing 5V. I threw it on the charger and went to work. Plugs were a little sooty but gapped correctly. Cold, I got ~150psi on all four cylinders.
I set the point gap, adjusted valve clearance, and changed the oil. I hit the head and valve cover with some degreaser and went to town with Simple Green on the rest of the bike. I pulled all of the electrical connectors, cleaned them out, and packed them all with dielectric grease.
I pulled off the gas tank and made sure the petcock flowed well. I drained all four carbs. I dumped 1/3 of a can of a Seafoam into the gas tank, and let a little run through the carbs. I pulled each of the fuses and checked resistances across each of them - all of them tested good, but the main fuse seemed a bit dodgy - I'd lose connection if I moved the multimeter leads.
I put all the fuses back and hooked up a spare car battery to the bike's battery leads, since the bike's battery hadn't charged yet. I turned the key and...nothing. I pulled out the multimeter again and found 12.65V between ground and the left side of the main fuse. I found 0V between ground and the right side of the main fuse. I pulled the battery off, replaced the fuse with a known good (but too long) one, and tried again. Suddenly my Neutral and Oil lights popped on, as did my running lights. Fantastic.
After about ten to fifteen seconds of cranking and a couple little pops, it started up, and it ran and idled okay, but chugged a little when I gave it throttle. Afterwards, I checked each pipe temperature by hand to see how hot it was. Four, three, and two were even, but for some reason number one was cold. Oh look, #1's plug wire is hanging loose. Plugged that back in, started it up, and voilà.
I have a modern fuse box that I bought for my CB550 cafe project that I might throw on this to make sure that part of it is reliable. My initial plan was to flip this for a tidy profit and buy myself a nice TV, but I kind of really want to keep it now. The forks look good, the chrome is perfect, the only rust is on the passenger pegs, the tires are both in great shape, I'm a fan of the 4-2 exhaust. It just needs a slimmer seat and some superbike bars and it would be perfect. Maybe I'll sell my Nighthawk...I guess we'll see.
