- All the O-rings.
- The diaphragms. Both were inflexible.
- Cap screws. These had corroded somewhat.
- Vacuum Blanking screws. These were damaged from repeated removal.
- Throttle shafts and screws. The peening of the original screws meant that they damaged the brass threads on removal.
- Gaskets on cold start and float chamber.
- Main jet washer. These were a bit corroded.
- Throttle and cold start return springs.
A few pics of this:
Before: 35 years of gunk. Note the carburettor on the left has the cold start spring replaced with a pair of other springs.
Before: The carurettor on the left, with the darkened piston, is the one with the damaged diaphragm.
Diaphragms. The one on the right is so badly damaged I'm surprised I was able to tune the bike at all.
After: all clean, ready for reattachment.
A few comments:
- One of the main jet holders was difficult to remove, there was so much gunk in it that it wore the threads down as I removed it. It reassembled okay, despite this.
- I couldn't adjust the idle down on the LHS carburettor far enough to be able to set the idle mixture. I removed it from the bike and reseated the throttle butterfly, being more careful this time to ensure a good seal against the throat.
- I had no device to remove the peening on the throttle butterfly retaining screws, and damaged the threads on the shaft when I removed them. I replaced the shafts and screws and used lock thread on reassembly.
- I crimped the fuel hose attached to the LHS carb on reassembly and it got no fuel. Replacing that section of hose fixed the problem.
- I don't have a compressor so I used a can of compressed air and a can of carburettor cleaner.
- I found this youtube clip from "Boxer2Valve" immensely useful: · https://www.youtube.com/watch?v=MpBA6wimjLc&list=PLXo0yJ7WoKfvSNxo1uZU3qupxkkf9xU4w&index=5
- Probably I should've done this 20 years ago.
The bike is running much better, it pulls better and I think that the range has increased 20%.
