I have a charging problem that is defying every effort to solve.
I’ve posted this on my Belfast-2-Belfast-By-Bike post, but thought I’d try to get a wider audience to get an answer.
A couple of weeks ago, my bike wouldn’t start with the starter, but fired up immediately with the kick start. Thinking I might have left the parking light on or something, I simply rode it for the day and it seemed to start working again.
Then it did the same thing again. The voltage at this point was 6.5V and the charging system could only raise that to 7.5. I put it on charge overnight and the voltage recovered.
I checked everything out and was now getting 14,5 volts at 3000 rpm, so I thought it was puzzling but since it charging, all was well.
Not so. A few days later while almost at my destination the engine died and refused to start again, even with kicking. A jump start allowed me to continue the journey. I put it on charge and ordered a new battery to me next destination. I should have stayed put!
60 miles from “home” the bike died and again refused to start. I got roadside assistance and again a jump start worked. Worried that it was getting late and I would have to use my headlight, I opted, on the suggestion of the assistance guy, to get a battery from AutoZone. He checked that had one, took me there and brought me back to the bike. “Once you get your other battery,” he assured me, “you can just return this one.”
So I put it in and she off. Riding now in the dark, on wet roads and on the fringes of a storm I was most alarmed when my lights started to fade. I turned down to parking light only and continued. Eventually I was riding more or less blind, just about able to see the centre and the side lines on the road. I had little choice at this stage.
Anyway I made it to within 70m of my destination before the engine died. I pushed it the rest of the way and put it on charge.
Next morning the (new remember) battery was recharged so I took it out and rode about 60 miles with no problem. However I decided to investigate the cause of the problem as I cannot continue all the way to my journey’s end in Washington State with the possibility of a dead battery leaving me stranded at any moment.
So here’s what I’ve found. To remember is that I have fitted a 750A field coil, and my regulator and rectified are modern replacements.
Rectifier checks out; resistance and connections at the alternator check out; Ground is good judging be no drop in voltage when measured at the battery -ve and a distant point.
Starting with a battery at 12.8V, it dropped momentarily to 11V when I pressed the starter.
The measured voltages, with no load were:
1000 2000 3000
12.6 13.3 13.5-14
After the test the voltage was 13.1V
I then repeated the test with headlight main beam on - standard halogen bulb
1000 2000 3000 4000
12.3 12.5 12.7 rising. 12.9 rising
12.3, 12.5, 12.7 and rising and at 4000 rpm 12.9 rising.
I measured the current flowing from the fuse and it was:
4A at 1, 2 & 3000 rpm unloaded and
8A with the headlight on at 1000 & 2000 rpm.
Then I unplugged the white wire at the regulator, and connected the ammeter.(red to terminal and black to wire) It read 0.2A.
When I changed the connection to the +ve battery terminal, there was no change.
Next I disconnected the green at the regulator and jumped black to white. Voltage at 3000 was 12.4 and steady. Removing the jumper made no difference.
I really don’t know what to make of this. On the one hand everything seem to be working, but on the other not so:
With no load battery voltage rises with revs as expected
With a load the battery voltage doesn’t rise
The alternator seem to be putting out an appropriate current, rising when loaded
The individual components - field coil and alternator don’t seem to be working
I am leaning towards a faulty regulator so will go now and remove it, but any thoughts in the meantime would be appreciated.
Sean
