Went out yesterday after opening up the seat and looking at the battery. No physical signs of problems. I start her up (first time in like 5 days), and she turns on no problem. I turn her off and start her again, again no problem.

I gear up and go for a ride on the freeway. Ride about 20 minutes and stop at friends place. I turn bike off and chat with my friend for about 5 minutes. Time to go, I press the starter and ergh ergh ergh sound. Weak battery. Nearly dead. WTF...all my lights are working great though. So I find a hill and do a roll on jump start. She starts fine and I ride home in 15 minutes. I stop and turn off. I turn her back on and she has no problem starting! Repeat, no problems.

Ugh, the battery seems to be fking wtih my mind. At first the battery gives me no trouble and cranks and cranks. But 20 minutes later it is deader than dead. Then 15 minutes later it is resurrected in all its previous glory!

Ever since I got back from Korea the bike has been giving me trouble. I've had the bike die on me twice at stop lights, dead battery after filling up at gas stations, etc.

What I want to know is if this is just symptoms of a weak battery (battery is a year old), or could this be a rectifier (R/R) issue?

Please help and thank you in advance!

I know this place is for non-specific tech questions but just wanted people to know my bike is a 1997 CBR F3.

Edit:

I've been looking at Havoc's guide for Diagnosing Charging System and will work from there. But I was hoping some of you may be able to pinpoint the problem already. Thanks!

 

could be the internal circuitry of the battery but sounds like it could be a recitfier tho startin to short out sometimes then goes and gets the battery some juice and sometimes doesnt and dead battery, three possibilities battery (unlikely), rectifier (probably), and stator (possibly).

 

hey man thanks for the help!

I've been actually doing some tests on my charging system and following a guide from one of our members->


"1. Use a volt meter to check your key off battery voltage and WRITE it down.

2. Unplug your rectifier, and connect your volt meter's black probe to the rectifier harness green wire, then connect your volt meter's red probe to the rectifier harness red/white wire and WRITE down the voltage.

3. If your step 2 voltage is less than your step 1 voltage, replace your 30amp fuse. If still lower, check your ground wire.

4. Test 1 and test 2 should be the same result... Tell us what you got.

5. If you pass step 1 and 2 (For example, both are 12.4 volts), then move forward.

5. Put your voltmeter on the ohm low scale (10 ohms or lower scale). With your rectifier still disconnected and your key still off, connect your volt meter's black probe to the rectifier harness 1st yellow wire, then connect your volt meter's red probe to the rectifier harness 2nd yellow wire and WRITE down the ohm value. Leave the your volt meter's black probe on the rectifier harness 1st yellow wire, but this time, connect your volt meter's red probe to the rectifier harness 3rd yellow wire and WRITE down the ohm value.

6. If your battery voltage is between 12 and 13 volts, and your step 2 voltage matches. Then it all boils down to the Alternator or Rectifier.

7. If your step 5 test returned 0.1 to 1.0 ohms between the 1st yellow and the 2nd yellow wires, AND 0.1 to 1.0 ohms between the 1st yellow and the 3rd yellow wires, than the RECTIFIER is bad.

8. If your step 5 test returned lower than 0.1 or higher than 1.0 ohms on either test, than your alternator windings are bad."

These are my readings =

Battery with key off = 12.73 Volts
Battery with R/R unplugged = 12.73 Volts
Battery with R/R plugged and engine idling = 12 Volts
Battery with R/R plugged and 2,500 RPM = 13-14 Volts
Battery with R/R plugged and 5,000 RPM = 14.1 Volts



Now, I need help running the tests to see if I have a bad R/R or alternator.

I set my multimeter to OHM (the omega sign) but I did not know for sure which yellow wire was 1st, 2nd, or 3rd. So I did tests on all of them in every combination but the readings puzzled me (can someone tell me how I know which yellow wire is 1st, 2nd, and 3rd?). The readings I got were either constantly 0, continuously rising, and or went up and down (i.e. from 3 back down to 0). Mostly, the readings were zero.

Am I setting up my multimeter incorrectly or are those readings correct?

 

OK...
You passed steps 1 and 2.
Now you must complete step 5...
All three wires tree into one another through the stator windings.
So... pick one of the three wires (your choice) and call it 1.
BE SURE YOU ARE ON THE RIGHT OHM SCALE. (the omega sign 10 ohms or lower scale).
BE SURE YOU HOLD THE PROBES STEADY. Moving them or change touch pressure will cause the ohms to jump around.

Try it and tell me what you get.