Battery or something else?

[mikesaa309]

Hi all,

Back in January the battery died in the GSX and I stuck it on charge but pinched the battery out of my Bandit 600 that my dad now rides so that I could go out. Put the GSX's original battery in the bandit and I've kept the bandit's battery and they've both been fine but for the last couple of days the GSX has been turning over slowly.  Today though I headed out and got to a fuel station and when I went to start it, it didn't fire up. Luckily I was with my Dad on his CX500 and bumped the GSX. Surprised how easily it bumps. We stopped for a leg stretch after a while and it wouldn't start again.

Put multimeter on the battery when I got home though it had been sitting for about 15 mins and the voltage was at 10.18 and didn't seem to drop. I got the battery of the bandit and put it in the GSX and it fired up just fine and I put the multimeter back on the battery, held the revs at around 2-3 rpm (though not sure as I didn't look) but we have a small garden with houses either side and it gets loud lol so didn't wanna hold the revs too high. The voltage went from 12.13 to o 12.25 though shouldn't this be more 13-14 volts when revved or is it depending on how much the engine is revving?

I'm hoping nothing like alternator or reg/rec is broken. I'm gonna get a new battery and see if it happens again but just wondering if anyone knows if it is just the battery or maybe something else?

[seth]

As I always say check the obvious stuff first like frame and motor earth's for good condition and connections .
Also the plugs behind the side panels and in the headlight.
Also what seams to becoming more common is the connectors to the ignition switch.
Then I'm afraid you are looking at the reg/rec or alternator.

Good luck hope you find the problem and it's a minor one 

[Hooli]

That does sound like a charging issue but as Seth says start with the easy stuff.

The manual shows how to check the stator output, I think they should be about 60v AC between any two yellow wires at 2-3k rpm. You can get stators for £55-60 now so it's not as bad as it was to replace them. Testing the reg/rec is easy with a multimeter, it's just a pig to get off the bike to do so.

[mikesaa309]

Well I stuck the battery on charge overnight and it seems to be holding it's charge at 13 volts. Guessing something is up with the bike then? Is it normal for stators to fail on the GSX at 50k miles? Though suppose just one of those luck of the draw things.

Also if it does turn out to be the stator, where is the best place to get one from?

[Hooli]

Is it normal for stators to fail on the GSX at 50k miles?

I fitted my third stator at around 120k miles, I think the first failed at about 80k. They aren't unknown to die, normally they burn out. I've never had to replace the reg/rec.

[mikesaa309]

Is it an easy job and is there anyway to do it without having to empty the oil?

[Hooli]

Stand it upright on centre stand or paddock stand etc, the oil doesn't fall out then.

I'm sure there is a guide on here, somewhere in the technical section. Just don't trap your fingers behind the cover as the magnets are strong & use a screwdriver to lever the crank around a touch if the starter gear falls out.

[T250]

Hope this might help as I have had issues in the past with an old Brit bike running E.I and they are susceptible to low voltage problems - this should point you in the right direction - you could always take it to a garage to have the battery properly tested.

Using your voltmeter just check the voltage if it is under 12.5 volts,the battery will need some more charging.

Don't bother testing without a fully charged battery,you will get a false result!

12.5 to 12.8 is fully charged. If you just took it off the charger and it reads above 12.8 volts, let it sit 30 minutes or so to dissipate this "surface charge"

Connect the battery up to the bike, and connect the voltmeter to the battery. Turn the headlight on to high beam.The voltage should drop to just over 12 volts. Leave the headlight on for three minutes and monitor the voltmeter. It may drop to just under 12 volts,but it should stay above 11.5. If it goes below 11 volts at this point, and it was fully charged to begin with,it's junk. After 3 minutes turn off the headlight.

Now you are testing "recovery". After 2 minutes(no longer),reconnect the voltmeter. It should be back up to at least 12.5 volts.If not replace the battery.

While passing this test will not necessarily eliminate your battery as a cause of your problems, if it fails this test,you know it's bad,so there is no sense in going further until the battery is replaced.

[grog]

T250, you speak the truth. Very good. An added bit is use your starter motor for load test. 12.6-12.8 must be standing volts. Cranking volts must be 9.5 min. Some cars, Honda is one, need at least 10.5 cranking. Otherwise bin the battery. 👍