Newbie on this board (but not to bikes or engines) and first original post...
Just got my '76 CB400F fairly well dialed in last night. This was a local garage find. Had been stored for 20 or so years. Had a flat rear tire, dead battery (natch...), broken starter button, a solid layer of dust and the tank was off. PO *swore* he had turned off the fuel, run the carbs dry and then drained them before rolling it into his garage.
Right...
Got a battery and a new right switch assembly and installed it. Then, it didn't take long to figure out the carbs needed an OH. Tank was kinda grungy, too, but it's borderline as to whether it needs to be recoated. For now, I'll leave it be.
Took a few weeks of part time work, four carb kits and a gallon can of carb dip to go through the rack and get everything back together. Installed new fuel and carb drain hoses, along with new o-rings in the rack. I'm happy to say there were no parts left over after reassembling the carbs...
Changed the oil and filter. Rear tire was an easy fix: Tighten the valve core. Brake pedal wouldn't return, but freed up easily with a little spray lube.
Once the carbs were back on, it started right up. But it had no "ass," as they say. It would peak out at around 5500 rpm or less under load. Tore the carbs off again and went through them, again, but didn't really find anything wrong. Timed it, put in new plugs (new points and condenser are OTW...). Still wasn't right.
Attacked the ignition and found an aftermarket plug cap with no resistance and varying resistance across the others. Put new NGK caps on it yesterday morning and discovered #2 jug was cold. Had spark, so the carbs came off again. Pulled the #2 slow jet and -- as I figured -- there was a speck of dirt. Blew it out, put it back together and all was well. Leaned it out so it would rev -- amazing how small-displacement engines are so sensitive to mixture settings.
Rode it this evening around the 'hood. Much, much better. Not dialed in, yet, though. Need to adjust the main linkage and then equalize the carbs.
But it's rideable and mostly purrs. Especially up around 8500 rpm...
<grin>
So, another one has been resurrected. YMMV...
fb
