If the impulse coupler spring breaks, you have, at best, a dead mag. If you
don't notice the subtlety in flight (as I once did) you will notice it as a
dead mag on your next run-up.

"JJS" jschneider@remove socks cebridge.net wrote in message
...
So far everything looks very good except for two things. My A&P IA was
inspecting the propeller spinner back plate and was turning the prop real
slow by hand as he did so. He noticed that the impulse coupler on the
left mag wasn't clicking. He turned it a little faster and it works fine.
Tried it slow again and sometimes... no clicky. Since I've had no
starting problems, he suggests I just keep flying it unless it begins to
give trouble. The mags won't be due for overhaul for at least another
year. My question is: Is there a slow death type "normal" failure mode
in which progressively harder starts occur or do impulse couplers usually
fail suddenly and leave you stranded? I really don't want to throw away
money. On the other hand I'd rather not get stranded after dark at an
airport away from home with no mechanics around or parts to be had.
--
Joe Schneider
8437R
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