Electrical Help

[aeonaeon]

Hi,

I have been experiencing weird RPM issues on my 2009 FZ6R. Basically, the tachometer would randomly spike 1k-2k RPM below/above real RPM at steady throttle, would drop to 0RPM while riding or idling. It has no effect on the motor, still very smooth.

I was reading and found out a bad battery may cause this. I go to check the battery, and it is over 18V (while bike was on, I check it when I disconnected it and it is still 18V)! It is not really bulging or bubbling or anything, but there was significant died battery acid on the positive terminal and a bit around the battery. I started thinking it was a bad rectifier/regulator, but I pulled it out and tested it. 2 sets of open circuit (1) and 2 sets of 750mv. Which seems to imply the rectifier works correctly?

Battery is Interstate Battery AGM Cycle-Tron II YT12B-BS, manufacturer May - 4 (I assume 2014, but it gives you a single digit for the year).

I have 2 general questions:

1. Assuming a 18V battey is bad, what would be the next step in figuring out why I'm overcharging the battery (should I test the rectifier while it is running).
2. Would my RPM troubles be mostly explained by a 18V battery?

Thank you for any help.

 

[Final Impact]

If your system voltage capped at 18vdc, every incandescent bulb in the system would have died!

Your lights would be really bright. Are they?

Allow the bike to sit for 4 hours. Read the battery voltage.
Ideal is 13.0v +/- 0.1
Idle: 12.8v
3500 rpm : 13.4 to 14. 3 depending on battery state of charge.

That said, I think your meter is defunct! Test a car battery, a 9 volt battery, a usb charger, a 12v power supply on a computer....

That is not to say it is not high! But 16v will make a battery bulge.

As for the tach bouncing, it could just be a bad connection. Inspect everyting buy pulling apart the connectors and looking for damage.

 

[aeonaeon]

If your system voltage capped at 18vdc, every incandescent bulb in the system would have died!

Your lights would be really bright. Are they?

Allow the bike to sit for 4 hours. Read the battery voltage.
Ideal is 13.0v +/- 0.1
Idle: 12.8v
3500 rpm : 13.4 to 14. 3 depending on battery state of charge.

That said, I think your meter is defunct! Test a car battery, a 9 volt battery, a usb charger, a 12v power supply on a computer....

That is not to say it is not high! But 16v will make a battery bulge.

As for the tach bouncing, it could just be a bad connection. Inspect everyting buy pulling apart the connectors and looking for damage.

Never buying Harbour Freight junk again, measured with a new multimeter and get 12.8 with bike off. I'll let you know if I find something with the tachometer, thanks!

 

[Marthy]

You should not see anything over 14.0 Volts. Test load your battery first and dig deeper if this is not the problem.