Electric testing

[magg]

Although the alternator output voltage readings look ok, I would do some resistance checks also.

Measure resistance from one of the yellow wires to chassis, should measure infinity. Measure the resistance between each of the three yellow wires, should get 1-2 ohms.

[bikemonkey]

Okay so, voltage across the battery bike OFF = 13

voltage across the battery bike using starter motor = 10.4

voltage across the battery bike ON = 12.4

voltage across reg/rec plug yellow wires = 42-44

Havent got any resistance readings yet as the bike won't start, battery been on charge for two days whilst in the bike, spark plugs clean and no blocks etc in the fuel system. Taken the battery off the bike to charge, then I'll try again tomorrow.

But can anyone fathom why the bike won't even start?

[magg]

Resistance readings are made without engine running. Just probe between pairs of yellow wires and then from each yellow wire to chassis. Yellow wire to yellow wire should measure approx 1 ohm and yellow wires to chassis should be infinite ohms.

Does the engine crank when you press the start button?

[bikemonkey]

Yeah the engine cranks fine, should have mentioned that I haven't been able to check the front plugs because of their awkward position, but the rear plugs are fine, little coked up but I cleaned off the contacts. And the bikes been stood for about 4 months, but allowed to run and warm up and idle for a bit every couple of weeks.

Shall go and do the resistance readings in a mo.

[bikemonkey]

So resistance readings are : each wire to frame = infinite

each wire to wire = 1.0 ohms exactly

[magg]

Your measurements indicate a serviceable stator. I thought the bike was running but the battery was going flat when the ignition was OFF, now you say the bike will not start. I am a bit confused.

If the battery is still going flat, you need to measure the leakage current. Disconnect the battery _ve lead from the chassis. Set your multimeter to current (you may need to put the probes in different sockets on the multimeter). Connect the +ve multimeter probe to the end of the -ve battery lead and the _ve multimeter probe to chassis. You should measure only a small current of a few milliamps which will be from your alarm unit.

[bikemonkey]

Yeah sorry the battery's going flat while the bike is left standing. Haven't actually got her out on the road yet due to the fact my final test isn't til Monday.

I'll get onto the current tests sometime today, would there be anything else worry checking while I'm at it?

[bikemonkey]

So I got back into the garage, I started testing from the battery lead to the frame in series, and couldn't get any current readings at all, no matter what way round I had the leads on my mulitmeter or which current setting I had it on.

But I did get some readings when my multimeter was set up like this :



The voltage readings fluctuated from 4-10 volts constantly rising and falling slowly.

I then bumped into the starter solenoid?



And this somehow when nudged or moved about triggered and turned off the alarm, so I took a further look and noticed that the two wires leading away from it had screws holding them down that were not tightened properly so I tightened them up.

After tightening the nuts up I took the readings again, but had the change the scale on the multimeter, with the leads still in the same sockets I turned the dial to 20 on the white scale and it read 13.2.

Then I tried again to get some current readings, I changed the red (positive) lead on my multimeter to the 10ADC hole and switched the dial to 200m Amps. It read - 49.9.

That's all I've tested so far.

[magg]

The two nuts that were loose are the main power feed to the starter and the electrical system. This may be the cause of your problem, the battery may not have been receiving a full charge and conversely the starter may fail to rotate due to lack of battery current, which would appear as a flat battery. The 30 Amp main fuse is located in the solenoid/starter unit, it can become a bad connection with time, worth checking also.

[bikemonkey]

Checked all the connections in the starter solenoid and the fuse, all okay.

When the battery does drain, it can drain so badly that it won't even light the oil and neutral light on the dash.
I'll keep an eye on the battery though now I've tightened those nuts, just to see if that was the cause of the drain.

But weren't the current readings from the negative battery lead to frame a cause for concern or not?

EDIT : Plus the battery didn't seem to charge properly when on the optimiser when in the bike, but it charges fine when taken out of the bike. Have left the battery on the trickle whilst in the bike for the mo.