I've got an 88 CBR600 with about 54K on the clock, 4k that I've put on since getting it in November, and recently it's decided to stop charging the battery.

I'll ride it around to the bank, school, whatever, and eventually it'll stop starting. Jumping/bumping it and keeping the revs up has worked pretty well, except once when it started chugging and finally died on the road. Pushed it to the girlfriend's, grabbed a spare battery, and no problems getting home. Each ride will drop the battery charge from 13+ down a little bit, until at about 12.2 it won't even start without a bump. A full charge will drop to about 12.8 after the first 15 miles--keeping it above 5k as much as possible--then the next 15 to about 12.5 or 12.4, then I've been switching out the battery to the charger and putting the spare on.

I've done all the electrical diagnostics the Clymer manual says.

The battery at full charge off the 2A trickle was at about 13.08. Pulled negative lead and instead of the 8v that the manual says to expect i got 12.5 or so. Pulled the plugs and got a nice flat 0, but the manual says if they're both wrong then the battery is bad. This is the second new battery, since the first replacement didn't keep charging anyway and I figured it might just be a bad battery.

When the bike is warm and running, the voltmeter between the terminals doesn't read the 13.5-15.5 it's supposed to at 5k, more like 12.6 to 12.8, depending how high I get it in the revs.

The 3 prong gave .5 resistance across all 3, testing each combination.

The 4 prong gave the right readings, can't remember what they were off the top of my head.

Basically, I'm trying to figure out WTF is keeping me from feeling comfortable going and hitting the corners without expecting to get stranded thirty miles from home.

Bad rotor maybe? The connectors all look ok, possibly corrosion in the wires themselves? It's a gorgeous sunny day, please don't make me wait too long to hear what you who know much more than I do about this bike think.

-Dave

 

I don't have the clymer manual but download the factory service manual and see if that points things out a little clearer.

KongBastard

 

it could be ur stator is the weak..

 

have you tryed putting a metter on the battery to see it is charging and what it is putting in? had a rectify pack go on mine bit newer but simular prob. Are the wires clean to battery and earth one and making good contact, a lazy starter can be a prob but normally just slow to turn over most the time,

hope this might help
Paul