electrical help needed

[Jonesy :-)]

I dug up a spare rec/reg
but first I'll run the same tests again for repeatability and then chuck in the spare.
can a rec/reg fault be intermittent? or is it more likely to be a wiring/connection thing
I read the manual and how to test the rec/reg, WTF bit overwhelming for a nut n bolt spinner like me
apparently you need two multi meters as well
Any sparkies out there who have meter will travel

[excess.11]

As Pete has suggested that excessive voltage may point to the regulator/rectifier.......try replacing that.....then carry out the same tests and get back with the results.

[Jonesy :-)]

Ok, heres some numbers to crunch
straight off the charger I had 13.2 volts
Ignition on and dropped to 12.6v
start the bike and at idle got 12.9v
4000ish rpm and 16+ volts ?
same revs with lights on and got 12.7v
@ idle with lights on and got 12.3v
turned bike off and 12.8v
start bike again, 4000ish rpm without lights and 13.7v ? theres that intermittent thing right there
do these figures suggest anything to the spark arrestors out there?

[excess.11]

The voltage you mentioned....without the motor running....was needed to be compared ...with the motor running .....of which we don t have . Can you carry out this check and report back.
Try some different scenarios to load the battery as a second test by switching on lights/indicators.and checking voltage at the battery.... the more info the better.
If as you say the problem is intermittent.........the best solution if tests don t show a fault.....is to change out the most likely culprits one at a time and run for a period to see if it cures the problem.
Start with a change of battery if it continues to show a low reading and other tests show ok.

[Jonesy :-)]

Another bit of info
Before the first post I checked battery (w/out motor running) and got 10.8 volts, so the last run home must've been on battery power alone? while still in bike it has taken near 36 hours to get back to 13 volts with a 900mA charger.
Could there be a drain somewhere to make it take so long to recharge?
I'll start with the easy connection/earth checks first.
I don't think the battery has a "fault from new" issue as its about 12 months old and performed well till now.
Having the parts bike is definitely a bonus, no need to disable the other runner and possibly upsetting the delicate old electrics
 
Thanks for the direction Jeff and Pete.

[Jonesy :-)]

Thanks fellas
Been in in a hot tin shearing shed all day and a couple of frothy ones to wet the parched throat afterwards, will digest your words later and follow up.

Thanks
Jonesy.

[petejw1966]

hey jonezy,
as jeff stated check all the connections and wiring first,
but if u have a multi meter ill give u a few checks u
can do to help isolate the fault,
with your battery fully charged put your
leads across the battery u should read around 12.6 volts,
now crank the engine, the battery voltage shouldn't drop any lower that 11 volts
if it drops more that 2 volts, u have one or more dead cells in the battery,
now with the engine running rev to around 3500rpm the battery voltage should jump
up tp at least 14 volts, if the battery voltage remains the same, its usually a fault with the stator,
if the vaults jump to around 15volts or more its usually the regulator,
that should give u a start, then if u find anything, do a check of the individual part to confirm,
the manual has ways to check the stator etc,
hope that helps.

[excess.11]

Jonesy....start with the simple checks first......such as checking and redoing/cleaning up ...ground wiring at the battery/ frame/engine and multiple ground connections under the mounting screw on the voltage regulator/rectifier.
Having your spare bike there is a bonus for changeover parts.
Change over the battery from your other bike just to eliminate you don t have a faulty new battery........which has happened to me.
Change over the voltage regulator/rectifier.
Change over the alternator.
Check the battery voltage before starting and when running the bike with your multimeter connected across the battery.....note the voltage when you operate lights / indicators etc.
The fact that you mentioned that the problem is intermittent is not good.as the checks may seem ok under static testing.....until a load is applied or as you mentioned.or under hard acceleration.
Check the wiring and connectors/connections from the 2 wiring looms from the alternator....carry out the tests as per service manual.
Check when the brass connectors push into each other they are a tight /clean fit.
Check the fuse block connections and that the fuses are a tight fit.

[Jonesy :-)]

Recently my XS developed a problem that appears to be the battery not charging?
here are some smptoms
The tacho has always been very erratic, needle swinging madly from zero to fullstop and I believe this is connected to the alternator. seems to be worse when accelerating hard or in the over 4000rpm rev range
whilst riding if using blinkers the idiot light(s) are very dull and the blinker stays on solid.
when I came to a halt a couple of times ( after the dull idiot lights) the bike would cut out and need a push start, not even enough power to pull in the starter solenoid. but then when going blinkers and all electric gizmos like horns and lights were bright and  ok. So it also seems to be intermittent as well
Battery is relatively new and healthy
This problem  only developed on the home leg from phillip island, before this it has run faultlessly

Any ideas where to look first, and what and how to test. have multi meter but not qualified to drive it, so clear instructions also appreciated