Hi there,
Can anyone tell me how to test the resistance of the various windings in the alternator of a V50 engine with points-based ignition?
I have a multimeter, but don’t know which contacts to test, or what resistance I should expect between those contacts.
A picture would help if there is one available.
Thank you.
Try this
Russell
Can you tell me where the condensors are on my V50? The RAC man thought they may be failing, which might explain my recent break-down!
Hi,
From the insulation tests listed for the Rotor, what are the implications if I DON’T get infinity when measuring between the slip rings and the engine, and which leads should have been connected / disconnected when carrying out the tests?
Remove the leads that go to the brushes on the slip rings before testing - this disconnects them from the regulator. With these disconnected you should have open circuit from the slip rings to earth (infinity or very high Mega ohms) if you dont you likely need a replacement rotor. Same applies to removing the stator cables when testing the stator.
The condensors are normally next to the points back plate - the two cylinder shaped things next to the points in the attached images. Its possible that these may have been moved elsewhere
Generally a failing condensor makes the bike run rough at higher revs. You have two condensors (one or each set of points) so unlikely both gave up at the same time. A failing condesor will cause excessive sparking at the points.
Workshop manual for a Mk3 at
Russell
Thanks very much for your response.
What would be the effect of having a duff rotor or stator? How would I notice these faults when riding the bike?
The battery wouldnt charge if these were faulty - but the engine should run ok with a fully chartged battery until it goes flat.
If you have a running issue its more likely related to the Ignition system or carburettors
Does the charge light go out when the engine is running - if so your charging system is likely ok
Russell
To test if your bike is charging or not, start the bike and put your multimeter across the battery red to +ve and black to -ve. Set it to DC volts up to 20V. Rev the engine and the voltage should rise from around 12v on tickover up to around 14V at 3000 revs.
Failing condensors can affect the ignition and running of the bike but won’t have any influence on the charging system.
Issues I have had were a stuck brush, symptom was ‘sparkling’ ot ‘twinkling’ charge light, and no charging (had a dash Voltmeter), seemingly oddly, charging restored if clutch lever was pulled, and stopped when released, this was my old R80 and I (eventually) deduced a slight amount of crankshaft endfloat meant it moved forward slightly when clutch was pulled, which made one raised point of the brush (where it doesn’t normally run) make contact again…
Second time was failing rotor winding, symptom was gradually worsening charge (different bike but again I had a dash Voltmeter to show me) and again frequent dim charge light. I made it home but it got to the stage where I had to try avoiding using lights or indicators, as it was mostly running on battery only!
Both same Bosch excitation rotor system.
They should be screwed to the block below the points but you can replace them with ones fitted on the coils earthed to the frame (I did)
