battery power
 

after a good charge the battery holds a good 12.6 volts when running it shows 14.5 volts.
i think this means that the rectifier and battery is good?
have cleaned all my connectors down that way an all. so why does it still turn over slower than a slow thing. always starts but its a struggle

I had a similar thing when I first got my bike, Battery tested ok and charged ok but if it didnt fire first time which was slow it wouldnt start, new battery sorted it

Hello Glyn,

I had similar trouble, battery would not hold charge, so I bought a new unit (Yuasa). Problem solved.

Hope you get it sorted.

Regards.

An easy way to check your charging system is working properly is to observe a rise in potential across the battery terminals when you rev the motor. At idle it should be around 12.5-13 volts. Rev the motor to about 3-4000 rpm and you should see it rise to about 14-14.5volts and hold steady from there (as yours seems to be doing).

The battery might still not be very good insofar as it's capacity might be reduced or it's not holding charge - there isn't really an easy way to determine this other than by seeing if it runs down overnight or a period of a few days when the bike is left standing or by doing a rundown test using a test load.

If yours is struggling to turn the motor over then that tells me that really it is lacking in capacity and the ability to deliver a high current when demand is placed upon it. This is possibly because of a build-up of sulphate on the plates - there's no cure for that other than a new good quality battery.

Sometimes batteries can recover by cycle charging them.

Could be a high resistance connection between the battery and the starter but if you are sure all the heavy guage wire connections are clean then it's probably a duff cell in the battery.

If you get a chance to check the battery voltage as you press the starter button, check to see if the battery voltage collapses as you try to start but bounces back up to 12v when you release the starter button.

If this is what happens it's classic failed cell symptoms and it's time for a new battery.

If the battery voltage only dips a volt or so when you press the starter button but the starter motor still turns over slowly then the problem is between the battery and the starter motor.

I'd try shorting out/bypassing the starter solinoid and see how quickly it turns over then,

As Martini says it could be high resistance which could be down to a well worn solinoid, which in effect is a metal busbar that shorts the two studs together that the battery cable and starter motor cables are connected to
and with the current drawn involved it causes an arc which over time causes the surface to become pitted and carbonised, hence becoming a poor (high resistance) connection

Also to be considered are the stte of the Starter motor brushes and the condition of the Starter motor idler gear pinion which as Bradders found out can cause big problemswhen starting

thanks for all the helpfull advice
so far ive done nought, as ive been striping calipers doing timing belts de dusting clutch and generaly spring cleaning. been at it two weeks!!
any ways i was putting it away tonight after some more feteling and she wouldn't start at all. long story short i found a nearly broken wire on the alarm where it disapears back into the loom near the battery, fixed this and she starts better than ever, turned over perfectly.
is this just coincedence ? could a poor conection on an alarm have this effect?

Maybe. But broken wires tend not to cause battery drain. It could conceivably cause starting probs if it's part of the immobiliser circuit.