My 1971 Honda CB350 K3
Sunday, May 3rd, 2009
A few weeks ago I made the purchase of a 1971 Honda CB350 motorcycle. I have been riding a Genuine Stella scooter for about a year now and decided it was time for an upgrade. I have always loved the look of bikes from the 50’s 60’s and 70’s and decided that the CB350 was going to be my target. I came to this decision based on a few factors. First being price. These bikes are easily found for between $1000 and $2000. Secondly I wanted to be able to work on the bike and not have to spend all my time tracking down parts. The CB350 is one of the best selling motorcycles of all time and has a huge tuner community behind it. There are certain parts are not always easy to find but for most everyday problems you can find the part and someone who knows what to do with it.
When I bought the bike it was having some problems with the engine racing, I thought it would be a good first problem to solve. When I got it home I immediately consulted my Clymer Manual and removed the air filters and carburetors. I spotted the first problem immediately. There is a rubber diaphragm assembly usually called the Slide Diaphragm or the Vacuum Piston that had torn. This is responsible for lifting and lowering a needle that controls the flow of gas in the carburetor, it was torn on both cabs and needed to be replaced. Aside from the that the left carb was completely gunked up and the jets on both carbs were not set to the factory specs. So I immediately began scouring the internet for parts and advice and got most of it taken care of except for two snags. The rubber diaphragms are extremely delicate and upon installing the two replacements I managed to puncture both. An expensive mistake. Secondly the carb rebuild kits I ordered came with two slow jets that did not fit into my carburetor. The company I bought them from has no idea why.
Right now I am stuck waiting for replacement diaphragms, once they come I’ll be able to see if I solved the engine racing problem. Until then my living room smells like gasoline and coffee table is covered in tiny brass parts. Kind of nice actually…
