Jessican wrote in "I'm not the most mechanically inclined person so I need someone's help."
This site of Mike G's is a great place to seek C70 help.
Jessica noted "the engine was sputtering really bad - could barely get
it up to speed to shift into 2nd gear and when I did it started to sputter out and die on me. I chalked it up to bad gas. Fast forward to today and it's still sputtering so I added some Sta-Bil to the tank hoping that would help things out"
Sta-Bil is wonderful for long-term storage but it will not help diperse water or non-fuel chemicals in gasoline. STP gas treatment and other products that contain a little alcohol are designed to blend mositure and fuel so the water passes through the carb and is burned.
Jessica also noted "had plans to drain the tank and refill it if that didn't work."
You carburetor may have ingested some very small particles of dirt and also some water, which would accumulate in the flaot bowl. You should consider removing the float bowl and cleaning it out. That is a good time to flush both fuel lines, too. It is possible the old girl has clogged the jets in the carb with some of the trash it picked up.
Jessica added "I started noticing something smoking under the right-side cover. Took that off and after going through my owner's manual
realized that it's the rectifier - it's very hot to the touch and the plastic seems to be a bit on the melty side (I assume that's what's causing it to smoke?).
The C70 engine has two separate "generators". One supplies power to the ignition system, so the fact she sputters - which could be caused by the ignition system - is in fact separate from the other generator.
The "other generator" powers the headlight bulb, and the high beam indicator in the speedometer. It also charges the battery through the rectifier, then the battery powers the horn, electric starter, stop lamp, flashers and other dash lamps.
The rectifier could smoke for a couple of reasons. It may have simply failed, and needs replacement. It may be a sign of another problem such as a short circuit or defective battery.
The simple test: turn the ignition switch ON but do not start the engine. Do the dash lights work? How about the stop lamp? Flashers? Horn? If the battery is defective, or if your bike has a short cicrcuit, you will notice. Perhaps the battery is low. If you can charge the battery, and pass this test, then you probably just have a bad rectifier.
Let us know how its going, the group is quite helpful and you can most likely get any repair made with some patience.
Jon Pardue
Sarasota, Florida
1970-73 C70 Honda Service Manual: http://tinyurl.com/6ebwtw
1970-73 C70 Troubleshooting Guide:
http://tinyurl.com/6ebwtw (scroll to sec.7.1 page 101.jpg)
1980-83 C70 Honda Service Manual: http://tinyurl.com/hu42c
1980-81 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec.18-1 page 170.jpg)
1982-83 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec. 20-28 page 205.jpg)
1980-81 C70 Maintenance Schedule: http://tinyurl.com/z4zn6
1982-83 C70 Maintenance Schedule: http://tinyurl.com/hw35c
More resources for C70 Passports and Cubs:
http://www.shlaes.com/Vehicles/Scooter.htm
http://www.velodrome.com/HondaC70/HondaC70.html
