Stick coils...are they that crappy ? (BMW part guarantee question)

[Beebop]

Just a little history on my 1150.
Bought Oct 2010 with 36000 km.
At 40000 started running eratically. I suspected stick coils, sent to BMW they did the 40000 service and
said I must try it out. I wasnt happy with the result.
Booked back into Auto Alpina, the kept it for 2 days, and eventually replaced both stick coils and said I
must try it out. Well it ran perfectly, so they charged me only for the 2 coils at "cost" That was at 44000km.

Over the past month or two, I have the same symptoms returning again.
Bike now has 72000 and its been 17 months since they were replaced.
I called Auto Alpina and they say I must bring the bike in and they will run
diagnostics. If its the coils they will submit a guarantee replacement to BMW, but
will need the service history since replacement. If its not the coils, they will charge me
R620 odd for the diagnostics.

Now my questions are:

1. Is 30000 a reasonable life for a stick coil ?
2. Why would parts guarantee be dependant on service history ?

I'm temped to drop the sticks completely and use a standard dual output bike coil
and run HT leads to the plugs, but thats another story.

 

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