Topic: 80 CB650C HELP!! Picture Included

[RyanRX7]

Well here's the deal, ran fine before then today I took it out for a ride and it wouldn't rev above 7,000RPM at first, and now 6,000RPM. Noticed the battery was low and only puting out 10volts. The charging system didn't seem to be kicking on either. Is that because it needs a 12v supply until the system will work correctly?? Are these problem related? It seemed like the more dead the battery got, the lower the bike would rev out to. One more queston, if you take the seat off and look at the battery, there are two small boxes with a plastic like casing melted in the back of them. The plastic stuff seems to have melted out as well, what are those and what do they do? They have been that way since I've owned the nike and never caused trouble. Thanks guys.

[RyanRX7]

anyone??

[Ibsen]

 I have the same bike as you have, even if they don't look alike. Mine is a Eoropean Z model, but otherwise it is pretty uch the same.
It is likely that a low power will cause a running problem. I have not experienced it on my 650, but I have on my other bike that also have an electronic ignition system. It happend when I got a short in the stator and it failed to charge the battery. So the first thing you should do is to get the battery tested. Most auto workshops have got a battery tester. And if it turns out that the battery is still useful, you will have to charge it and the do some tests of the charhing system. You will need a workshop manual for those tests. Or you can download a fault finding diagram from Electrex: http://www.electrexusa.com/electrex_fault_finding.html

The parts with the number 38 is the main fuse. And the two black boxes under the seat are the spark units.

[cb650]

I agree with Ibsen



               Terry

[98zr67]

the 2 small boxes you are referring too are the igniter boxes for your ignition.

[Ibsen]

the 2 small boxes you are referring too are the igniter boxes for your ignition.

That might be the correct term. I only had a Clymer manuel as a reference.

[cb650]

try takin the side cover off and maybe the air cleaner cover.  Have heard that this is a problem seen it first hand on a bike in the shop. havent had to do it on any of mine though.



                  terry

[El Taco]

Those are the ignition modules. I altered a 75 CB550 plate and advance to fit my 81 CB650C and converted it to points just so I wouldn't have to pay far too much to replace those cheesy little modules. My bike ran fine, or okay. Then again, when the modules went out, it didn't run at all, but they were melted like that.

[CHUNG]

We call them "CDI Boxes" although I'm not actually sure that it is a CDI IGN. They tend to either work or NOT. weak sprk isn't an option, no spark when they fail.
This "late model" stuff is kinda new to me but I'm the Ole Honda Guy so they send the Dinosaur bikes to me. Hell, a 1977 is a newer bike. LOL More likely that the Rec/Reg failed and low voltage is why you are missfiring. You can check the diodes but you have to have the bike running to test the regulator.
Check static voltage, turn the key on, fire the bike, rev the bike. You should have at least 10.9 VDC static on a very bad day. A 10% drop when you flick the switch ON is normal. It should never drop below 9ish VDC while starting and you should get more voltage after it's running than when it was static with the key OFF.
If you get a slight rise in voltage when revving but still less than the staic reading then the reg is bad. A voltage rise to 13VDC isn't unusual although lower than we want to see.
I had one that read 11.6 at rest, 10.8 @ idle but a rise to  11.3 at revs. The Rec/Reg was bad. But there are other options, the Reg is failed although the rectifier is still good. RICK'S sell these items seperate although I have yet to figure out how to intergrate them into the Honda System. He's a cool dude and I'm sure that he will offer this info if I ask?

[Ibsen]

It seems like the black boxes have got many names. The Haynes manyal refers to them as amplifiers.