2003 CBR600RR: Starts fine, turns off, won't start

[TheQueenIsDead]

Hey there, first post and a bit of a rookie in the repairs department, go easy on me!

Was wondering if anyone can help me diagnose an interesting issue with a CBR I picked up recently.

The Symptoms
This morning I turned her on, started pretty-a-ok, let her run up to temp and then headed to work.
Was driving for about 15 minutes, then stalled her at the lights (2nd time on the bike :facepalm:).
Tried to start her again, but had to wheel her onto the footpath and bumpstart.
She did turn over, maybe once, and quite slowly, sounds like the battery was just not giving her any juice.
Once she was running, I drove the remaining 2 minutes to work, turned her off in the carpark, then tried to turn her on and start, but same story, no crank.

EDIT: Went out to show the colleague the new toy, about 2 hours after turning her off. Wasn't sure she would start again, but she did. Almost wondering if it's more about
something heat related after running under load....Weird that it didnt start after being turned off, but given time popped back to life.

I had this happen when filling her up with petrol on the way home from purchasing her on Sunday too so I thought I'd take a look at the battery health.

Battery Investigation
Whipped out the multimeter, turned the bike on and let her run up to 70c.
While running she had about 13.x volts.
Turned the bike off, and she dropped to 12.8v
2 minutes later -> 12.5v
4 minutes later -> 12.42v
7 minutes later -> 12.40v
17 minutes later -> 12.37v
30 minutes later -> 12.33v

At the 30 minute mark, I turned the key to On, and the voltage dropped to ~11.5v, a bit low for my liking

She still started up being that low, and after running for a few seconds jumped back up to 12.37v.

And of course, being yesterday I tested this, she turned on fine this morning, I didn't grab a voltage reading.

===


It's looking more like it's an issue after running, heat perhaps? Any words of advice on what to check, or if the numbers gathered about the battery yesterday are helpful / concerning?

Thanks in advance!

[slofox]

A new battery might fix all that. But a faulty charge system might also be lurking in the bushes somewhere...

Good luck

[TheQueenIsDead]

A new battery might fix all that. But a faulty charge system might also be lurking in the bushes somewhere...

Good luck

Cheers pal, yeah I was wondering about a new battery, she's been sitting about for a bit without a trickle, and the voltage dropping to 11 when switched on is a bit naff.

Just throws me that she will start after not being ran.

Might grab the tools again tomorrow morning and check the voltage after being in the garage overnight...Not sure I'd know where to start with diagnosing issues further than the battery eh

[TheQueenIsDead]

Cheers cobber, hoping it's just a naff battery, wouldn't have a clue where or how to start looking for a leak.

Wee update as I can't stop thinking about this issue at work lol, found this thread about a guy that had it much worse than I do:
https://www.vfrdiscussion.com/index.php?%2Fforums%2Ftopic%2F84532-voltage-drop-when-on-on-position-bike-wont-start%2F

He just needed a new battery even after seeing some super weird stuff happening there (0v????).

Some other pal also gave rough estimates on what the voltage should probably be for a healthy Honda:

12.8 or higher is a good battery...
12.0 to 12.8 is a insufficient charge... recharge...
12.0 or lower... battery unserviceable...

Given I was sitting at 12.5 most of the time, potentially time for a new one. Might compare how the voltage looks on my Enfield battery when home, though it doesn't have HISS running in the background, simple machine ;-)

Could be keen to take the battery to the shop for a quick health check from a pro, will see how we go

[F5 Dave]

You should get mid 14point something on a semi modern bike when revved to 3000rpm. Battery would be pretty rooted to drag it down. Probably 13.7 at idle.

Check again with more revs. Should build up and hold still. If the regulator is poked it will go through 15v. Honda regulators are a bit suspect.

Battery sounds kuzed anyway.


If it won't get high enough when revved can go over testing stator AC voltage.

[pete376403]

Batteries do recover (a bit) after running low, but its not something that can be relied upon

[FJRider]

Cheers cobber, hoping it's just a naff battery, wouldn't have a clue where or how to start looking for a leak.



Borrow a battery off a mate ... see if the same issues occur.

Cheap and almost pain free ... :lol:

[TheQueenIsDead]

You should get mid 14point something on a semi modern bike when revved to 3000rpm. Battery would be pretty rooted to drag it down. Probably 13.7 at idle.

Check again with more revs. Should build up and hold still. If the regulator is poked it will go through 15v. Honda regulators are a bit suspect.

Battery sounds kuzed anyway.


If it won't get high enough when revved can go over testing stator AC voltage.


I'll give that a go and see what she's like when revved, cheers pal.

Took the battery down to a local SuperCheap to borrow their health checker, tests said the battery was fine, but it is from 2012, probably due a replacement about now haha.

The guy at the shop also mentioned that the regulators can be a bit iffy, I reckon that's the next port of call after swapping the battery, thanks for the input everyone, good to get given specific numbers to look for, rather than just guessing myself

[F5 Dave]

When regulator fail they generally fail by allowing over voltage.

2012 battery is very old, I'd replace it anyway. Is Supercheap tester more car based? Can it pick up plates moving causing internal intermittent problems? This last bit is more a theory but battery can do some weird shit.

To test the stator if output is low when revved you unplug it at its connection from the cover into the main loom, looking carefully at the condition of the plug contacts. Turn meter to AC and check between all combination of Yellow (or all same colour wires). Should be within a few volts of each other maybe circa 50V AC. If any are lower then you have an issue. Bound to be YouTube vids.

[TheQueenIsDead]

When regulator fail they generally fail by allowing over voltage.

2012 battery is very old, I'd replace it anyway. Is Supercheap tester more car based? Can it pick up plates moving causing internal intermittent problems? This last bit is more a theory but battery can do some weird shit.

To test the stator if output is low when revved you unplug it at its connection from the cover into the main loom, looking carefully at the condition of the plug contacts. Turn meter to AC and check between all combination of Yellow (or all same colour wires). Should be within a few volts of each other maybe circa 50V AC. If any are lower then you have an issue. Bound to be YouTube vids.

Appreciate the advice!

Did a bit of testing, got the bike on and hooked up the multi-meter again, she got up to 13.3v at 3k rpm and stays there at 5k rpm, didn't jump past it. Sounds like the regulator might be happy enough.

I reckon the SuperCheap battery test is more for cars yeah, taking it with a bit of a grain of salt there. Have asked Mega Motorcycles to get a new battery in for me, will replace it when one arrives :woohoo:

Thanks for the info around checking the stator etc, will be sure to embrace my inner Youtube mechanic if the battery doesn't do it

[F5 Dave]

Recheck with new battery. But you'd expect it to be getting a bit warm if it was dragging the voltage down that much. Still a bit concerned with your stator until this check.

Also pull on that wire from alternator and check the plug to the main loom.

[TheQueenIsDead]

New battery arrived, had left the CBR for a wee bit as the weather was miserable and I'm a pansy

Old battery was fully dead and gave half a crank. Was at 11.7v and dropped to 11.05v with the key in the on position.

New battery was a fresh 12.8v and dropped to 11.7v with the key in the on position.

Started first pop, took her for a ride to the beach for some vanity photos, turned on again first time.
Rode home, got to the garage, turned her off, imeediately started her again and all was well.

Very happy that it's fixed at the moment. Proof will be in the pudding if the battery doesnt get knackered within a few weeks of being installed. Will see how we go.

Many thanks to everyone for their input, highly appreciate it.

Now to sign up for the next MCI have-a-go day at Ruapuna :Punk:

[pete376403]

Any aftermarket electrical accessories? Any ghetto wiring? (some people cannot leave a standard wiring loom alone) ammeter test could tell if there is any battery drain when key is off.

[TheQueenIsDead]

There is a power command to supliment the akrapovic system, nowt that I can see apart from that. Tidy install and the rest of the bike is the same, nothing too ghetto haha.

Ammeter is a good idea, catch it before finding out later

[F5 Dave]

Re perform the voltage tests you did before so you have a measurement.

[Fisher]

I wonder what the problem was in the end?