Charging issue

[Centaur]

I agree about expert reps, John.....however...

1 He is getting a good ac voltage across all three phases.
2 He is showing no connection between any phase and earth on ohms.
3 He is now getting a decent voltage across the battery with headlight on.
4 A leak caused by poor insulation between windings would not short to earth but would show as reduced ac voltage on that phase and certainly would not account for ac between coils and earth. Only connection between the coils and earth could do that.
5 The only POSSIBLE fault is BB SAYS he is getting airy fairy readings between windings and earth but admits he is not the worlds most experienced electrician (Sorry BB).
6 Do you see any particular reason why he should not try riding the bike especially with a meter to watch the charging level.

Hides from storm. h1d1ng2

 

[Jaws]

No.. he is NOT getting decent volts.. Only JUST acceptable volts

At 5,000 rpm the volts drop to around 13.6 DC across the battery, but that may still be due to the bad news. Turned all lights on and indicator and still getting around 13.4 at 5,000 rpm so enough to run.

 

[bishbosh]

Well, I think I will go with it as after the discussion I don't have the confidence they will accept it as a warranty failure and I need to use the bike soon.

If it fails in the next 12 months, we can rightly go back to them and say they gave the OK to use it but obviously it was on it's way out.

 

[Centaur]

I bet you ?20 if he changes the alternator again it will not get rid of the "problem". :-0)

 

[Centaur]

If you happen to ride up to Aberystwyth, BB, I'd love to stick a meter over your bike. @tu* :-0)

 

[bishbosh]

A quick update

I had a few occasions where I reconnected the terminals and things go back to normal 14.5v tickover and 13.5 ish with lights on and 5k revs but after a while I would lose charging.

I finally got round to making up a bypass lead - WOW!!!

15.1 volts at tick over only dropping to 14.8 with all lights on and 5k revs.

So my problems are the loom connectors and I'm also thinking about starter relay as last time I inspected the 30 amp fuse the blades looked worn.

 

[Centaur]

Hoooooooray, BB.

Wiring corrodes with age and resistance builds up and eats some of your available power. I have bypassed the loom on many bikes and achieved the same result. As you say, I agree you should take a hard look at the starter solenoid as the next problem may be reluctance to start. I bet it is pretty corroded. I worked with Petros in Greece on an intermittent starting problem on his Blackbird which we eventually narrowed down to corrosion on the lead from the starter button to the solenoid. Corrosion was eating up voltage which meant sometimes the power was too low to operate the solenoid. It was fun working with Petros on Skype. All's well that ends well. :-0)

 

[Wolfman62]

This sounds worrying similar to my problem, I'm going to do the loom fix and test again, I have not tested for voltage from yellow wires through to earth as yet though.

 

[bmwdumptruck]

Bill and John
Hope you guys don't mind(orBB) but can I ask for some advice on the same topic?

I'm trying to get my mates heap of a vfr750 back up n running. It's a 91ish model and has caused quite a few issues over the last couple of years. I've not done anything to it previously, my mate just fitted a new battery and initially a SH honda RR followed by a cheap chinky RR, against my advice, but he's not got any money to spare due to a house move. The chnky RR didn't last much over a week and cooked the new battery too.

John, you may recall my mate Andy, he collected a stator and RR from you for my 2000Bird back in about 08, and took it with him to Nice where I had ground to a halt. Now I was never sure my RR had failed and had kept it as a spare, as my bike just ground to a halt from a lack of charge. As it's now not compatible with my later model FI I've fitted it to his Vfr this morning.

To start with I fitted a new battery, cut the melted plug off the loom, fired the bike up and tested across the three phases as you suggest. At tickover on choke it was showing around 40-41v AC on each phase at around 2500rpm. That sounds a bit high to me, I seem to recall you say 24-25, but can't recall at what revs.
Having just read through this thread I realise now I didn't test each phase to earth as you recommend.

As all three phases were the same I carried on and spliced the three yellow wires to the Bird RR. Which I guess now means I can't test to earth unless I cut them again?

I then fired the bike back up and measured the output from the RR across the red and green wires. I'm getting a steady 20v DC, but that's with no load.
I carried on and spliced the Reds and greens together, fired up again, headlight on main and I'm now getting around 18v DC, again fairly steady.
Pretty sure this is too high?
But is it the RR or is the stator too high and the RR is unable to regulate it down enough?

For the record I'm using my Fluke multimeter that I'm told was top of the range when new. I use it frequently for work and believe it to still be pretty accurate.

I'm guessing I'm going to have to push my mate to get a mosfet RR?

Thanks in advance for any help/advice you can offer.

 

[CBRDEAN0]

Bill and John
Hope you guys don't mind(orBB) but can I ask for some advice on the same topic?

I'm trying to get my mates heap of a vfr750 back up n running. It's a 91ish model and has caused quite a few issues over the last couple of years. I've not done anything to it previously, my mate just fitted a new battery and initially a SH honda RR followed by a cheap chinky RR, against my advice, but he's not got any money to spare due to a house move. The chnky RR didn't last much over a week and cooked the new battery too.

John, you may recall my mate Andy, he collected a stator and RR from you for my 2000Bird back in about 08, and took it with him to Nice where I had ground to a halt. Now I was never sure my RR had failed and had kept it as a spare, as my bike just ground to a halt from a lack of charge. As it's now not compatible with my later model FI I've fitted it to his Vfr this morning.

To start with I fitted a new battery, cut the melted plug off the loom, fired the bike up and tested across the three phases as you suggest. At tickover on choke it was showing around 40-41v AC on each phase at around 2500rpm. That sounds a bit high to me, I seem to recall you say 24-25, but can't recall at what revs.
Having just read through this thread I realise now I didn't test each phase to earth as you recommend.

As all three phases were the same I carried on and spliced the three yellow wires to the Bird RR. Which I guess now means I can't test to earth unless I cut them again?

I then fired the bike back up and measured the output from the RR across the red and green wires. I'm getting a steady 20v DC, but that's with no load.
I carried on and spliced the Reds and greens together, fired up again, headlight on main and I'm now getting around 18v DC, again fairly steady.
Pretty sure this is too high?
But is it the RR or is the stator too high and the RR is unable to regulate it down enough?

For the record I'm using my Fluke multimeter that I'm told was top of the range when new. I use it frequently for work and believe it to still be pretty accurate.

I'm guessing I'm going to have to push my mate to get a mosfet RR?

Thanks in advance for any help/advice you can offer.

I would say by those readings that stator is good - R/R is scrap.

 

[bmwdumptruck]

Did you check to see if there was a measurable AC voltage between an earth and the three yellow wires ?

They should all read zero volts..

I read it that you had done this check but now unsure if I read it right ?

So further to my recent post89 above, I've unsoldered the phase wires between the stator and RR and have now tested as above.
At rest I'm getting nothing, no resistance, and no circuit or continuity.
But with engine running at about 2000rpm I am getting around 15volts AC.
It's showing around 30v AC between each phase, but 15 between each phase and Earth. So I Take it that means I need a stator?

 

[andyBeaker]

So further to my recent post89 above, I've unsoldered the phase wires between the stator and RR and have now tested as above.
At rest I'm getting nothing, no resistance, and no circuit or continuity.
But with engine running at about 2000rpm I am getting around 15volts AC.
It's showing around 30v AC between each phase, but 15 between each phase and Earth. So I Take it that means I need a stator?

Yes - but that it good news as a) you have found the problem (exactly the same as the last episode I had on my FI) and b) changing the generator is easy. Don't forget to order a new gasket!

 

[andyBeaker]

And some self amalgamating tape to seal the multi plug - the short roll that B&Q sell works well.

 

[bmwdumptruck]

And some self amalgamating tape to seal the multi plug

Not got one of them Andy!! It kind of disappeared....... but I'll wrap the loom back up where I've soldered all the connections, once I'm happy with it.

 

[Centaur]

Hello BMWDT. Thanks for the pm.

There should never be an ac voltage between any yellow wire and earth. The coils are wound on metal with the "lacquer" insulation on the copper wire keeping it insulated. If the coil overheats for any period the "lacquer" melts and the coil is no longer insulated from earth. the voltage at 40 would be a bit too high for a Bbird but may be normal for a VFR if the rotor magnet is stronger. In any case the stator is knackered. I bet the burning will be obvious when the stator is exposed. Have a sniff where the wires come out and you may smell burnt lacquer. This means the reg/rec will have been working harder than design so may also be damaged. Change the stator and test again. On any old bike it is always best to wire direct from the reg/rec to the battery via an inline fuse. Having replaced the stator if the top voltage coming out across the battery is above about 15 volts then the reg/rec is also knackered or unsuitable and the battery will be fried in a VERY SHORT TIME. Alternators and reg/recs are matched so just changing to any mosfet reg/rec would not necessarily suit. If the output with a new stator is too high then the correct reg/rec must be fitted. Preferably mosfet but there are plenty of scrap VFRs so a second hand one should be available if money is tight.

 

[andyBeaker]

There should never be an ac voltage between any yellow wire and earth. The coils are wound on metal with the "lacquer" insulation on the copper wire keeping it insulated. If the coil overheats for any period the "lacquer" melts and the coil is no longer insulated from earth. the voltage at 40 would be a bit too high for a Bbird but may be normal for a VFR if the rotor magnet is stronger. In any case the stator is knackered. I bet the burning will be obvious when the stator is exposed. Have a sniff where the wires come out and you may smell burnt lacquer. This means the reg/rec will have been working harder than design so may also be damaged. Change the stator and test again. On any old bike it is always best to wire direct from the reg/rec to the battery via an inline fuse. Having replaced the stator if the top voltage coming out across the battery is above about 15 volts then the reg/rec is also knackered or unsuitable and the battery will be fried in a VERY SHORT TIME. Alternators and reg/recs are matched so just changing to any mosfet reg/rec would not necessarily suit. If the output with a new stator is too high then the correct reg/rec must be fitted. Preferably mosfet but there are plenty of scrap VFRs so a second hand one should be available if money is tight.

Does that mean it is sensible practice to replace all three components when the charging system plays silly buglers?

p0pc0rn41


When regularly changing the components on both my Birds I rerouted the wiring so as much as possible was under the seat as a) it helped keeping it out of the weather and b) makes the job easier next time it all needs replacing.:cry:

 

[bmwdumptruck]

Pic of stator. Quite a lot of lacquer breaking off and one half is well darker than other

 

[Centaur]

Smell it, BMWDT.

Pic of stator. Quite a lot of lacquer breaking off and one half is well darker than other

It should smell burnt in that top LH corner. Does not look good to me! :cry:

 

[Centaur]

[QUOTE=andybird;788958]Does that mean it is sensible practice to replace all three components when the charging system plays silly buglers?p0pc0rn41


When regularly changing the components on both my Birds I rerouted the wiring so as much as possible was under the seat as a) it helped keeping it out of the weather and b) makes the job easier next time it all needs replacing.:cry:[/QUOTE]

Only if you are rich enough to sit in bars in Nice paying inflated prices for gnats piss which the French laughingly call beer and sell to rich foreigners. 8rfl@

 

[Clayshooter]

Just a thought

Hi BB, when you are measuring a few volts AC between the alternator phases and earth with the yellow wires unplugged, are you using an earth point on the engine or on the frame / battery?

If you are using a frame / battery earth point this may account for what you are seeing if there is a bad engine to frame earth bond.