1983 CB750C DOHC Charging Issues

DMalikhain

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Hi, i'm new around here and i'm sorry in advance for my english 'cause it's not my native language. Anyway, i've recently purchased a 1983 CB750C DOHC, at first when i brought the bike home it lasted solid 30 minutes, then i came back to the garage and it stalled down. Gone through all the posts and found out my rotor, stator and regulator were way all out of spec. I've recently replaced all of 'em and right now i have a digital voltmeter attached to the handlebar that gives me the current battery voltage (i know it's not safe, i've only gone through empty street as of right now for test purposes). The meter reads ~14v when in 2nd gear and pushing above ~4500rpm and ~14.4 - 14.6v when above 3rd gear and pushing at least 4500rpm again. Could that be an issue and be depleting my battery? I've done those tests with the headlights on low and cruising for 30min max. Any suggestions will be highly appreciated, i've read a lot of times about rotor going bad when running due to centrifugal forces and resistance going up when hot, but that doesn't seem my case 'cause when going above 35mph it seems to be charging well and holding charge, also the Honda service manual gives ~14v spec when above 5rpm but i found a guide online where it says that i should get around ~14.4v even at 3000rpm so i'm scratching my head right now. Thanks in advance to anyone who'll try to help!
 
Good question. I don't hit 14V until around 2500-3000 RPM. But once I get there, I rarely go over 14V. But that is just mine. I believe the manual says it can go to ~14.5.
I’m sorry if I ask you but what’s your rotor’s slip ring’s resistance? Mine is 5.2 ohm when cold and around 6 ohm when hot (I thought that could be the issue). Also, I run an AGM battery and I don’t know if my system could support that cause I read that AGM needs stable 14.8v to charge.
 
You might be looking for a problem that is not there. These charging systems are simple. I don't think I have seen two bikes the same. You will also get different results between multi meters. If you have access to a couple of different meters, try them. You might be surprised. It sounds like your bike is charging as good as anyone else's. Cleaning connections can sometimes change your results slightly as well.
 
You might be looking for a problem that is not there. These charging systems are simple. I don't think I have seen two bikes the same. You will also get different results between multi meters. If you have access to a couple of different meters, try them. You might be surprised. It sounds like your bike is charging as good as anyone else's. Cleaning connections can sometimes change your results slightly as well.
Okay, thanks for the answer I’ll try to make the connection as clean as possible!
 
Check the white slip in plug that comes from the charging side of the bike. Under the left side cover. 4 pins. I’ve had 2 bikes get bad connections there. One was so bad it melted the molex plug.
If bad, cut the plug out and just wire nut it.
 
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