The Patient: 1980 Honda CB 900 C, stock except for Jardine 4 into 2 headers, being restored after 3 years abandoned in garage. 30,000 miles total.
Condition and Treatment so far: Carbs replaced with overhauled unit by reliable shop, and synced to bike. (Original carbs were cleaned, but still popped as noted below; were never tested at high rpm.) Jets stock at 105, running in Houston Texas at sea level and 80 degrees F. Compression all excellent. Valve clearances all within specified tolerances. New plugs D9EA (recommended). Plug wires checked for 100% continuity. New battery: Alternator output 12 amps at 14.5volts, battery voltage at 12, coil voltage at 11.2, Pulsar gap to .016, static time checked Ok. Waiting on new timing light for dynamic timing. (Note: Pulsar was gapped with metalic gauge, although not magnetic.)
She runs fine except:
Problems: #1 When no accelerating (ie. loafing along, not much load on engine or backing down) get popping on right side Jardine, some times a lot of popping. Not full backfire, but a lot of popping.
#2- Main problem: On opening her up, whether off the line, or on the highway, at 7500 rpm, power just quits. Will not go above 8000. Can sneak up on 8000 at less than full open throttle, but then same problem and will not go above 8200. Pulling on some choke makes no difference. Ran at 6500 for 2 minutes -- lots of popping on right side-- shut down and pulled 1 and 4 plugs immediately. Very light beige color, with a touch of pink(?). Absolutely no oil or soot or black. Possibly too lean due to Jardine headers??? Would that cause these symptoms?
Diagnosis?
2007-04-24
16:23:18
·
6 answers
·
asked by
Tom Michale
1