Alan,
This does not need to be a big problem at all. There are some relatively
simple checks you can run to establish whether the alternator is a fault
or not.
If you have the use of a good quality multimeter, measure the resistance
between the two YELLOW leads to the charging coils of the alternator,
that can be found at the multi pin plug on the top of the engine. You
should get a reading of between 0.1 and 0.8 ohms (this is a very low
value so you will need an accurate DVM/AVO/multimeter).
If the resistance is below this, the insulation on the coils could have
begun to fail and the windings short to each other. If the value is
infinity, then the coils have failed completely - both will require a
new stator.
Check also each YELLOW wire to ground. The correct value should be
infinity. If you get any reading, then the windings have shorted to
ground (though this unlikely, as you are getting some charge at the moment).
If you would like to learn more, download the Rotax 912/914 "Heavy
MaintenanceManual" from the following site (foc):
http://www.rotax-owner.com/en/support-topmenu/engine-manuals
Refer to Section 74
Read Chapter 3.7 (on page 16) for an explanation
Compare the results with the values found in chapter 3.12 (on page 22)
That should keep you amused for the weekend!
Nigel
On 24/07/2015 22:18, Alan Carter wrote:
>
> Hi Greg.
> This is becoming a big problem, I can see the panel voltmeter move slightly as
I increase power, but you are right its not maintaining my battery.
> With the volt meter across the battery at cruise power its only 12.8v.
> Now we come to fixing it, sodding built in intricate mag/alternator on the
> back
of the engine,
> I was expecting a bolt on Alternator replacement unit, insert the shaft and
> tighten
up the 4 bolts , JOB DONE, same as the a tyre change on bloody main wheels,
have to unlock and unbolt the disc to change a tyre,
> Took me longer to do the wire locking than it did to fit the new tyre.
> WHY ??
>
> Anybody repaired the Alternator on the 914.
>
> Regards .
> Alan
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=445165#445165
>
>
|