My 1971 CB350 K3
I own a vintage K3. These bikes are very common, since they were the best selling commercial motorcycle of all time, due to their low initial price and ease of modifying.
I find the turn signals are tough to keep running, mostly because of their location on the back of the bike, and the way they poke out like Bing Crosby's ears. Passengers tend to smack them hard with their feet when mounting the bike. The stalk and buckets are made of metal, which helps them stand up to the abuse, but I replaced mine with bullet lights mounted off of the tail light. The flasher is current-run, so no replacing them with LEDs unless you add in a controlling circuit.
The carbs have a tendency to overflow, and require careful maintenance on a schedule. Running a bit of seafoam through them helps, if done once at the beginning of the season. Never leave old gas in the tank, as this almost guarantees a carb cleaning or rebuild. Luckily, carb rebuild kits are plentiful and very cheap. Check the rubber boots for dry rot and cracks, especially underneath. Small tears can be super-glued until new boots can be located.
If you're thinking of buying an old CB350 twin, check the clutch pushrod seal. If yours is near the sprocket, they get a lot of gunk and wear out, causing a good bit of oil to leak out. You can change the seal without cracking the case, but it's a pain to do.
The brakes are drum, front and back. Pads run 18K miles easily, and if you're not brake-happy, can easily run 25K before needing new pads. They work well, unless they're overheated, in which case they fade away.
These old twins will not win any races (unless you're racing other old twins), but they're stable, can easily get over 70K miles with religious maintenance, and are very reliable machines. They make an excellent (cheap) first bike, and can run highway speeds with no problems. Top speed is 102mph, but that's pushing things. My bike averages 65MPG when running at 55mph, and drops ten MPG when running on the highway.
These bikes are fun, and it's worth having one to play with if you have room in the garage.
Last edited by Guy; 09-12-2007 at 08:32 AM.