Topic: '82 CB650 weak starter

[Z-MO]

So I am helping out a buddy with his CB650.  He hadn't run it in about two years.  We put a new battery in it and the starter sounds weak like its not getting enough juice.  We put the charger back on and let it sit overnight, same thing.  I jumped the starter solenoid to see if that would speed it up a bit but no avail.  Anybody have any suggestions as to the next step?  He is popping a fuse for "meter/taillight" that we haven't chased down yet.  could that be a cause?  Electrical is my weakest area of knowledge with these bikes, any advice would be much appreciated.  TIA. 

[tomkimberly]

Do the basics, check and clean all connections and grounds.

Tom

[Rgconner]

Yep, probably voltage drop across dirty contacts or burnt/broken wire.

Try taking voltage readings at each junction, see if it is still 12.6V or has it dropped?

Voltage went into my key lock at 12.6, came out 9ish. Had to clean up the internal contacts to get it back up to 11, ended up doing a relay bypass.

[MiGhost]

A weak starter is often due to carbon dust buildup, and worn brushes inside the starter. Pull it apart, clean it, lube it, and replace the brushes if need. Also check all the cable connections for proper contact, and resistance. The cable that runs from the solenoid to the starter can get pinched causing the wiring inside to break down leading to a high resistance short.

[trueblue]

Hook a jumper cable direct to the terminal on the starter, if it spins up easily, the problem is in the wiring on the bike.  If it is still lazy, it is the starter