Topic: 1980 CB650 out of storage and sorta running. Need help.

[diskman]

I dug my 1980 CB650 from storage the other day and decided to start throwing money at it again.  It has 25K miles and has been garaged it's entire life so it's in really good shape.  After throwing about $800 in parts at it in the past week (sprockets/chain/brake pads/electrical crap/oil/all filters/tire/on and on.  Here are the problems that are still haunting me.

The battery won't stay charged.  This is my second battery in 4 days and it will maybe crank the starter for 2 seconds before going completely flat.  I measured the voltage at the battery when idling and it's about 14.8 volts so some juice is getting to the battery.  I have since removed all the main wiring and solenoid and sanded all contacts till shiny and reassembled with CRC Electronic Contact cleaner spray.

After replacing one of the "Pulse generators" that has been giving me fits for the last 6 years, I finally get all 4 cyls banging away now reliably.  However, I get some nasty hesitation and idling is a long shot unless the choke is out or it's 85 degrees outside.  I cleaned the carbs yesterday, (Pulled them off and disassembled with air / carb cleaner and Gunk degreaser/dip.  I still think it feels "lean".  Now what?  Do I need to pull them again and clean again??  I replaced the fuel line and inline filter and rinsed out the tank yesterday too. 

Any ideas?  I have never adjusted the valves or cam-chain so I will hit those tonite.


Heres a pic.  You might need to cut/paste into your browser as my hosting people are kinda flakey lately.
http://www.atgig.com/slack3r/picts/cb650.jpg

[Robert]

I have the same bike. 14.8 V sounds good, just to be sure you can disconnect the red wire from the bat and connect an ampere meter between the positive pole of the bat and the red wire that goes to the solenoid (when ignition is OFF). It should read no more than 2 mA. Otherwise there's some batterie draining going on which needs attention. (ignition switch, handle bar switches are some ideas to start)

I suspect the starter motor as the culprit. It's easy to remove and to disassemble, just jot down where all the things belong when tearing it apart. If you need a drawing I can send you one. Give special attention to the two carbon brushes inside, there's maybe some old carbon residue inside the starter motor that builds up  resistance.

Would not fiddle with the carbs (how did the float bowsl look?) before adjusting camchain tension and valve clearence. Also the timing (pulsers) needs to be spot on. Maybe this is all it needs.
With the engine off, adjust both pulsers seperately, so that they allign exactly with the advancer "tooth" at the 1.4(2.3) F-S mark. Reach for an 0.2 inch clearence between pulser and advancer tooth.

Great looking bike btw.

[diskman]

UPDATE:

Man it's late.. 3:25am and I am still messing with the bike.. Sheesh.  Here is what I found so far..

Step 1
I pulled the solenoid and decided to pull it apart since it was veery rusty and corroded.  The contact points inside were slightly black but not hosed.  I hit them with the brass wheel anyways.  I then re-constructed the solenoid and re soldered the electro-magnet power wires etc and re-installed on the bike. 

Step 2
I then tried starting again but it still clicks like a dead battery after about 2 seconds of turning over.  I then tried just jumpering the control lines on the solenoid and that worked great!  The starter will crank and crank all day now, so the problems NOT the solenoid or starter or main wires from the battery.   It seems that the two control lines, (green/red - yellow/red) that control the solenoid are not sending enough juice.  I only get 5 - 7 volts between them when pressing the start button.  The starter button DOES show about 100 Ohms resistance instead of a direct connect.  Looking at the wiring diagram, the start switch runs through the clutch switch and some other safety switches.  Lame.  I will have to trace it all tomorrow I guess.  Either that or wire a new switch in. :p