I don't have a discharge

[Plugsnpoints]

No funny comments please...

My alternator coil ignition M16 appears not to be charging since reassembly.

It shows a decent charge when the LED lights are on. A bit less when not on.

It had a new battery fully charged, a new PRS8 switch and nothing different to what it was before the tidy up of the bike. I put a new Colin Farrington wiring loom on ages ago and everything worked before. The only 'mistake' if you like was an incorrect stator connection when I first fired it up after hibernation. That was soon fixed, The stator is the original non resin type,

It worked fine for the first 100 odd miles then started misfiring so had to push her home for the last 1/2 mile today .

Any suggestions please before I fork out for a new stator and rectifier?

Thanks chaps and ladies.

Andy

[Mick D]

Hi

Are you sure it's not charging? the ammeter seems to indicate as expected, (unless you have reversed the connections). Is it possible you have reversed the ammeter connections during replacement of the PRS8?

Do you have a multi meter to check the voltage at the battery? If you're seeing around 7V, (13.5V if on a 12V system), it's not the charging system at fault.

Have you considered/investigated a fuel issue, partially blocked jet etc.?

Have you confirmed the ignition side, do you have a fat spark from the plug?

Regards Mick

[Plugsnpoints]

Hi

Are you sure it's not charging? the ammeter seems to indicate as expected, (unless you have reversed the connections). Is it possible you have reversed the ammeter connections during replacement of the PRS8?

Do you have a multi meter to check the voltage at the battery? If you're seeing around 7V, (13.5V if on a 12V system), it's not the charging system at fault.

Have you considered/investigated a fuel issue, partially blocked jet etc.?

Have you confirmed the ignition side, do you have a fat spark from the plug?

Regards Mick

Hi Mick, thanks for replying. I'll put a meter on it today. It shows a discharge when I kick it over (as in when the points are closed). It also starts first kick and runs perfectly with a charged battery (7.4v).

It ran until I stopped off at the shop on the way home. Then it wouldn't start. There's not many hills in Essex to jump it on my own, hence the push. No wonder they're called heavyweights!

I am convinced (for now) it's a charging issue.

I want to know how to diagnose if it's the rectifier or stator at fault (or even the rotor?). All the connections are clean and sound as far as I know but I'll check.

It has a newish ammeter.

Andy

[Mick D]

I want to know how to diagnose if it's the rectifier or stator at fault (or even the rotor?)

Hi Andy

Easiest to check once your battery is re-charged so as you can start the engine.

To check the alternator, put your multi meter onto VAC and put it across the input terminals of the rectifier - you should see 7+VAC.

If you see 7+VAC the alternator stator and rotor are performing OK, (Confirm VAC lights on and off).

To check the rectifier put the multi meter back to VDC and measure across the output terminals, expect to see 7+VDC - no volts indicates the rectifier is fried if you are seeing 7+VAC at the input.

A bit of a long shot, but if you're are seeing a DC output it could be a bad earth at the rectifier mounting stud disrupting the supply to the battery.

Regards Mick

[clive]

No funny comments please...

My alternator coil ignition M16 appears not to be charging since reassembly.

It shows a decent charge when the LED lights are on. A bit less when not on.

It had a new battery fully charged, a new PRS8 switch and nothing different to what it was before the up

Andy

I would expect the ammeter to show less charge with even LEDs on, rather than with them off. Or at least that is what happens with my Dynamo powered system and LEDs front and back but perhaps alternator systems are different. With the engine off and the lights on does it show discharge? LEDs use so little current you may need to put a bulb across one part of the circuit to check if you have the ammeter correctly connected.

[Plugsnpoints]

Well, I've just put a meter across the newly charged battery.

It shows about 6.5v on tickover then climbs to over 7.5-8v ish when slightly revved.


Like I say, it runs a treat with a fully charged battery, and now it seems it's charging well. This is without the lights switched on. The ammeter shows a healthy charge when they're on.

Any ideas what would cause a drain?

The battery is losing charge (a brand new one last week). I had this problem with the old battery too so have eliminated a faulty one.

Would LEDs be upsetting the system? I have the old pre focus candle 24v/30 bulbs to try

Thanks,

Andy

[Mick D]

Hi

I think you have an intermittent fault or your rectifier, (probably), or alternator which is failing after a time in use.

Take the bike for a run and keep an eye on the ammeter, head for home as soon as the ammeter shows discharge and repeat the tests above.

What type of rectifier are you using?

Regards Mick

[Plugsnpoints]

Hi

I think you have an intermittent fault or your rectifier, (probably), or alternator which is failing after a time in use.

Take the bike for a run and keep an eye on the ammeter, head for home as soon as the ammeter shows discharge and repeat the tests above.

What type of rectifier are you using?

Regards Mick

Hi Mick, thanks again. the rectifier is the standard black LUCAS LU490726. I've just swapped the bulbs back to the prefocus and normal stop/tail, but no difference. It's still pumping out 7-8 volts when revved (this is across the battery).

The only indicator if you like is the ammeter needle swings wildly on tickover, then shows a charge when revved-lights on and off. It's a cheap Chinese Lucas one if that helps? I've just been looking for a better quality one if anyone has a recommendation?

Thanks

Andy

[Mick D]

Hi

The ammeter jumping around on tickover could suggest to me there is a bad connection somewhere which is making and breaking with the vibration, going away as the engine revs increase and the vibration decreases. Are you sure all of your connections are good?

Does applying gentle pressure/torque to the PSR8 have any effect?, (could be a dodgy switch).

My ammeter is a Lucas badged and boxed one, (part number 36084), supplied by Steve at AMC Classic Spares, I believe it is damped and was around £20 five years ago.

Regards Mick

[Plugsnpoints]

Hi

The ammeter jumping around on tickover could suggest to me there is a bad connection somewhere which is making and breaking with the vibration, going away as the engine revs increase and the vibration decreases. Are you sure all of your connections are good?

Does applying gentle pressure/torque to the PSR8 have any effect?, (could be a dodgy switch).

My ammeter is a Lucas badged and boxed one, (part number 36084), supplied by Steve at AMC Classic Spares, I believe it is damped and was around £20 five years ago.

Regards Mick

Hi Mick,


I've just ordered a good quality solid state rectifier as a cheap option to start with.



Thanks again Mick.

Andy