Customer from Baltimore, MD bought this mostly original CB400A. Never ran quite right, even with my CDI and Ignition Coil Kit. Eventually it stopped sparking, despite passing resistance tests. When it arrived to me I confirmed that static tests were good, but once hooked up to a Peak Voltage Adapter (PVA) it was obvious. The voltage windings (Blue and White) would read about ~150-200VAC for a revolution or so then immediately drop to 1VAC. Had the stator rebuild by Kirk at Custom Rewind in Alabama. In the mean time, hooked up a spare stator for testing and bike ran OK but was lacking in power and very loud. Took the valve cover off to adjust valves as part of the tune up and found the adjusters were completely unthreaded! Got things adjusted and what a difference. All that power came back and noise was gone.
A lot more was done to this including completely rebuilding the front forks, complete brake overhaul including DOT5/Silicone conversion, carb clean, and some wiring repair. Overall, a fun bike to work on.
Tag: Vintage Bike
82 CB450SC Nighthawk 450
A local customer. This 450 twin had over $800(!) at a local shop that rebuilt the carburetor and did a tune up. It never ran quite right, with a very obvious lean spot at 1/4 throttle. When inspecting the Jet Needle to verify if it had the service bulletin update it was found that the Jet Needle had a washer stacked in there. From here the float valves and height were checked. Confirmed to being using aftermarket K&Ls and a float height of 17mm. With OEM we now have a proper float height of 15.5mm. Compression was initially 155psi, after a full tune up we now have 175psi. Balancer chain adjustment was done as the bike has approx. ~10k miles.
Now runs very well. Nice, crisp throttle response. Pulls well through all the gears. Excellent handling and suspension after front fork fluid swap and regreasing swingarm bushings.