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Can't seem to keep the battery charged

Mikegg2643

CB750 Member
Messages
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Location
Kent, Washington
Hello All. All around new biker and first bike I bought was off a a buddy of mine for about 500 bucks was a 1981 honda cb750K. This bike is awesome. Honestly really enjoyed the THREE times I've been able to ride it. So the story on this bike is that it sat for three years before I bought it off my buddy. I changed the oil bought a new battery. Replaced the main Wiring Harness, both left and right control units. Regulator/Rectifier, Stator/Rotor and Brushes. I've pretty much replaced everything Electrical on this bike that I can because like I previously stated, it sat for three years and hand't been started. I'm planning on doing the plugs after If get my current problem fixed. I bought a new battery when I bought the bike. Filled it up to line on the battery and charged it but at first I was having issues with the charging system. So I replaced the Rotor and stator....I did more research on charging systems and electrical testing. i bought myself a decent Multi-meter and My battery after it comes off the charger at my house reads right around 12.76 but then starts to slowly drop the charge 0.01 every 5 sec. This morning, I hooked up to the bike plugged everything in. turned the bike on the reading on my battery dropped. When I tested it this morning before putting it on the bike it was reading 11.76V When I turned the bike on, but didn't start it, it dropped to 11.34V. When I tried to start the bike, the battery dropped all the way down to 7.56V and I have a feeling Its a bad battery. I have people testing the battery and before they say its a good battery just needs a charge but I shouldn't have to continue to charge my battery every damn day, just to use my bike. I feel like I'm starting to go crazy. Any help would be great appreciated on this situation.
 
So Quick update so far on this fun little adventure. GOt the battery back and it was tested and fully charge threw it in the bike and its holding steady. Looks like I my indeed though need to replace my entire wiring harness. Also now my running lights aren't working.
 
Nevermind Got the problem fixed. So far shes running great now. 20180422_195143.jpg
 
So final update on this issue.
I found out that after I replaced the stator and regulator rectifier. I burned those out a second time. After replacing both of those and a new battery. I also ended up needing to swap out my starter. After that. holds a charge. starts every time. No issues.
 
So final update on this issue.
I found out that after I replaced the stator and regulator rectifier. I burned those out a second time. After replacing both of those and a new battery. I also ended up needing to swap out my starter. After that. holds a charge. starts every time. No issues.
So what did the starter have to do with the charging system just curious
 
So what did the starter have to do with the charging system just curious
The starter has Its own ground to the engine block that the battery runs through when starting the bike. The Area in which the battery sits can get very gunked and the ground to the block can become fouled. Replacing the whole unit must have fixed whatever grounding issue that were occurring. It is possible that he may only have needed to take apart and clean the starter, but replacing it was probably the better bet.
 
So Quick update so far on this fun little adventure. GOt the battery back and it was tested and fully charge threw it in the bike and its holding steady. Looks like I my indeed though need to replace my entire wiring harness. Also now my running lights aren't working.
Which specific harnesses
 
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