My CB550 started life as a 1978 K model. By the time I got it, someone had swapped a lot of the parts from a donor bike. I'm not sure if the engine is the same, but the carbs are Heihin CR carbs from '74-'76 and not the PD carbs. The exhaust is a 4 into 1 from an F model. The gas tank is maroon, but the side covers are black. So it's anyone's guess exactly how the bike looked new.

To date, I've completed the following.

• Overhauled the fork bearings and rebuilt the fork tubes
• Replaced front wheel bearings and trued the front wheel
• Rebuilt the front caliper and master cylinder, and replaced the front brake pads
• Rebuilt the engine, split and painted the case, replaced all seals and gaskets, new piston rings, new primary chain and new drive sprocket
• Replaced the rear wheel bearings, trued the rear wheel, new rear sprocket, new brake shoes and drive chain
• Rebuilt the carbs, and replaced spark plugs
• Fixed the wiring due to it being hooked up incorrectly

On the left to do list:

• The original PD carbs had the vacuum port on the carb, where the CR carbs had the vacuum port on the intake manifold. Because I had PD manifolds with CR carbs, i had no vacuum ports to tune the carbs. A quick trip to Ebay fixed that, but then the intake diameter of the CR manifolds was slightly smaller, and the intake rubbers that were on the bike didn't seal, so I had to order new ones. The project stalled at this point. I still need to install the manifold to carb rubbers, adjust the carb floats and figure out the air cleaner and the carb to air cleaner rubbers that I was finally able to track down to replace the pod filters that were on the bike.
• I still have an electrical gremlin, as the turn signals aren't working like they should.
• Figure out the ignition timing
• Figure out what to do long term with the exhaust. The 4 into 1 F exhaust bolts onto the K frame, but you can't use the kick starter. If you install a kick starter from an F on a K, it hits the peg. When I tried to bolt on pegs from an F, they didn't bolt onto the frame as the bung for the peg is in a different spot on the K frame than an F. I did pick up a used 4 into 4 exhaust, but the mufflers are pretty rotten. I'm probably going to cut the 4 into 4 pipes down, and put on an aftermarket 4 into 2 exhaust once I get it running reliably.