With stars in my eyes I bought a 74 CB550 back in October. It ran when I bought it, although I didn't know how badly at the time. I wanted a bike, and I wanted a project. I got both. By December I got my M endorsement, but the bike no longer started. I was super busy with work at the time and didn't have time to tinker with it.
It got warmer and I got time, so I started messing with the bike. Charged the battery, wouldn't start, and wouldn't hold the charge, so I got a new one. Finally, I had a friend come by and help me get it started, but I noticed that only 3 and 4 were firing.
After much diagnosis and discussion I figured that 1 and 2 weren't getting fuel and I needed to rebuild the carbs. I was very anxious about this because I didn't know jack about carbs except that they were the cause of many problems if done incorrectly.
Finally I got them rebuilt and back on the bike. I adjusted the valves, adjusted the cam chain, put in new plugs, and charged up the battery. It started and ran for a few seconds. I figured that I needed to adjust the carbs and I would be ok. Just for the heck of it I touched all the pipes to see if they were all warm. Now only 1 and 2 were firing!
By now I knew that the 2 sets of carbs are fed by 2 different fuel lines and I figured that I still had the same problem as before only I had the lines running to a different set of carbs. So I took the petcock apart, cleaned everything really well, and made sure all the little passageways were clear. Oh, I also straighted the bent washer in the petcock.
Of course, that washer is supposed to be wavy! After leaking a bunch of gas all over the floor I realized that I had done something wrong. Luckily, I had another tank with a petcock that still had a wavy washer. (See, I told my fiancee that I really did need to buy that extra tank off ebay!) Saved me 48 bucks for a new petcock from the Honda dealer!
Finally, tonight I put everything together and to my great surprise it started on the very first kick! Whoa! It was idling at about 3-4k, but I was so surprised that it was running (and on all 4 cylinders too!) that I just sat there and let it run for a couple of minutes.
My senses came back and I decided to adjust the idle. It went down, but it went down too far and the engine died. I tried to restart it and it ran a little bit, but not like before. After trying to get it to start a few more times it will no longer start.
I checked the brand new plugs and they are black and sooty. I don't have the air filter on right now so that may be a problem there. I don't know why it won't start now. It's like it's not getting fuel again.
Fotunately for me, but unfortunately for my CB550, I have a job interview next week. I need to take time to prepare for it so I will not be able to troubleshoot until after the interview.
This has been a long, frustrating, but ultimately rewarding experience so far. All the frustration of the bike not running has been knocked out by the reward of learning to wrench on the bike and ultimately by the roar from the exhaust tonight. I've proven that it CAN run, now I just need to keep it running. I know that bigger rewards are in store in the future.
I just wanted to thank all of the people from this site and past versions of it for answering my questions and sharing their experience with all. And special thanks to Glen for getting this forum back up. It's great!
Thanks again,
Brian
