floyd850
CB750 New member
Yes but no spark. Only get spark after start button is released - crazy right.
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Intermittent High Voltage
- Thread starter millsmobile
- Start date
Sounds like your ignition is wired with the headlight switch. In other words , your ignition is getting power from the WRONG source.
Some bikes have the headlight in the starter switch. There are contact points in the start button that allow the headlight to light up, and when you push the start button those contacts are separated as the contacts for the starter are made. This turns off the headlight when the starter is used, preventing the headlight from consuming power that is needed for the starter motor.
Yeah
millsmobile
CB750 Enthusiast
So... My regulator tested fine at Ricks Electronics and they're sending it back to me. I talked to one of the techs and it sounds like this ignition switch is a likely culprit. I didn't ask about the measuring etc and how it works, but the tech explained if there's a voltage drop of 1v going to the regulator from the battery, there will be a 1v increase in output. He gave me some spots to check for voltage drop. I'm wondering also if maybe the starter solenoid could be causing a similar issue? Almost everything is wired through that and I'm thinking that could be another source of intermittent issues. Will update when I get the regulator back on the bike
millsmobile
CB750 Enthusiast
I got the regulator back on the bike and based on my notes from the tech at Rick's I did have it installed correctly the first time. I took the switch apart, and while it wasn't really dirty it's functionality and condition was somewhat suspicious so I ordered a new one. In the mean time I put a simple heavy duty toggle switch in it's place, mostly because it was 60 yesterday and I wanted to ride.
Unfortunately, it was not charging the battery yesterday. (on the plus side, no over voltage either) I started out at 13.2v fresh off the charger. It was sitting at about 12.8 when the bike was running, and the voltage slowly dropped over the course of my ride to low 12v, high 11. According to the app my headlight is the biggest draw, and shutting that off provides a bump but the trend was still downward. There isn't any surge in voltage when twisting the throttle.
Now what?
Cooked battery? Stator? Wiring shenanigans?
Unfortunately, it was not charging the battery yesterday. (on the plus side, no over voltage either) I started out at 13.2v fresh off the charger. It was sitting at about 12.8 when the bike was running, and the voltage slowly dropped over the course of my ride to low 12v, high 11. According to the app my headlight is the biggest draw, and shutting that off provides a bump but the trend was still downward. There isn't any surge in voltage when twisting the throttle.
Now what?
Cooked battery? Stator? Wiring shenanigans?
If you're not charging the battery with the stator, but you can change it with other means, your battery seems fine. And your stator checked out ok.
Have you checked all connections from the stator to the battery? Sounds to me like a poor connection between the two somewhere. Sorry if that isn't much help
Have you checked all connections from the stator to the battery? Sounds to me like a poor connection between the two somewhere. Sorry if that isn't much help
millsmobile
CB750 Enthusiast
Update: stator tested fine, battery tested fine and is taking a charge, however my brand new rotor I put on in August is cooked with just 600 miles on it. Glue chunks rattling around, play in the ends, no continuity between the rings, and a burnt / disconnected winding. At this point I can't be sure if the 17-18v is the cause of it's demise or a symptom. I'm leaning symptom since the weird over voltage issues were originally happening at higher RPM which to me lines up with a rotor failing due to centrifugal force. Guess we'll see what the next rotor does.
millsmobile
CB750 Enthusiast
Well it appears the voltage issue was caused by a new alternator failing. I put a new Rick's rotor on it and the voltage is perfect. The build quality also appears to be much better. The burnt one I took out had less than 600 miles on it. The epoxy was brittle and it was pretty clear they missed a spot.
