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[Gwilly]

Plus one with Mark and Ric..
A simple test (though not conclusive) would be to see if the headlight stays at the same brightness from tickover to 2000rpm when directed against a wall..

Should get brighter with increased revs.

If it does then perhaps 6 mile trips is indeed not enough to keep the battery in trim.

Suggest if the bike is garaged at night you should invest in a digital/electronic battery charger like the Optimate 4.. Just open the tool box and plug it in to the permanent connection to the battery that comes with the charger..

Simply unplug and start the bike in the mornings..

[Gwilly]

PS get that terminal soldered properly, Know its right then..

[jefrs]

It is most unlikely to be the alternator. The C5 alternator is a piece of work, it could probably run a kettle. It is certainly up to running the bike will all the lights on, additional lights and ancillaries plus using the electric wellie whilst keeping the battery charged.



Whilst the battery (FIAMM-India?) is a likely suspect, the export ones are pretty good. More likely are connections.



I found a number of corroded fuses and spade connections on my C5. The crimping was well done but the spades are thin and the plating poor, replaced.



The battery terminal connection snapped off. This is a strip of brass and it snapped clean across where it had been bent. Again, too thin for the job, sorted.



Any poor connection between alternator and battery will cause poor charging.

[Mr Black]

Well, it broke down again on the way home. Spluttering and backfiring and then non-starting. Had to wait 3 hours for recovery to come out which is just what you want on a warm sunny friday evening.

The guy did some checks. The alternator seems fine but he couldn't pinpoint the problem so I think i'll have to trust it to those that know. I'll let you know what they find in due course.

Thanks again for the input so far.

[Mr Black]

Well bizarrely it turned out to the the throttle cable that was causing the problems. Rusty living and a fraying inner.

I can't quite fathom why/how this could cause the backfiring and spluttering as it seemed to move pretty freely & smoothly, but cable changed and it now all seems to be ok.

On to the next one...

[jefrs]

I can't see the throttle cable causing that problem on its own but it would affect the way the throttle opens and shuts and that would affect the air pressure sensor, and the connections to those can cause similar problems - perhaps fitting a new cable nudged the adjacent connector back into place. Do check that connector hanging off the side of the throttle body.



Having fitted the AT-200 Autotune to the PCv on my C5 I can now effectively record and then see the Air/Fuel Ratio (AFR) from the Bosch wide band O2 sensor. Bit difficult to do it in real time with the laptop plugged in whilst riding it. What I can see from the numbers it spits out is the oem ECU map is all over the place. Since employing the AT-200 the farting popping and banging is virtually eliminated. The banging on the overrun is reversion - cold air being sucked into the hot exhaust and either simply expanding or igniting unburnt fuel, and apart from the odd "snap" that's gone too. Reversion is worst if you have an exhaust leak at the head.



The alternator on the C5 is really very powerful, certainly enough to run a full set of auxiliary spot lamps as well as the headlamp and still charge the battery. I don't often run the bike very far, only 1/2 hour today with pilot/idiot lights on. I nearly always use the electric wellie and I've never had cause to charge the battery. Batteries do die but no one mentioned checking the electrolyte level?