Hi, I have a 1977 CB400F that has been on the road for the first time in 20 years this summer. It is running well (with much help from this forum) but seems to be rich(?). The airbox and filter are stock, as well as the header. I am running a MAC muffler. It has a Dyna electronic ignition. The first thing I did about 1 1/2 years ago was to have the carbs cleaned and rebuilt by a reputable and Honda specific shop in the area. I adjusted the valves to proper tolerances, the timing is dialed in and the battery is in good shape. Initially I was fouling plugs after 100 miles or so. I opened the air screws to 1 3/4 turns and have stopped fouling plugs. The plugs are tan to light grey at the electrode, but black around the outer edge. I seem to getting 45-50 mpg. It is hard to know how the performance is as this is the first and only bike I have worked on/rode. This has been an amazing process to breath life into this old machine and I am grateful to be on the road and down to fine tuning. It initially had 8800 miles, but after a dry summer I am sitting at 10500. Should I look at the carbs? It was the one thing I did not personally do. I have read dirty emulsifiers could be the issue. After much searching I have not found much specific to the CB400F carb, and how and when to adjust needle height.
Also on a different note, I have had to straighten the swing arm that came on the bike as well as one from a bin of parts that I bought. Both where relatively east to straighten, but I am left wondering if this is a weak point on these bikes. Could the torque of the motor over time twist the "legs" of the swingarm, or is it really only an impact that would do that? Anyway, the wheels are now sitting plumb to one another and the bike, which makes the ride a lot more neutral. I am still getting some pull to the right however, even after setting alignment as accurately as I can. Is there some sort of rig for centering and holding the steering while checking alignment?
Thanks all for the continued help and advice...
