Remi and Rick,
The aircraft has EVERYTHING known to man to prevent kick-backs, including the
flywheel
with extended lugs. The CDI boxes seem to be working as advertised, at
least because the timing remains well retarded for several seconds after start
until the built-in advance takes over.
My engine seems to be one those which is just simply "accursed" by this problem,
to the extent that I fitted an additional separate cranking switch to facilitate
overcoming the inertia of the HEAVY Airmaster propeller hub and letting it
spin for a couple of seconds, before adding choke when cold or sparks when warm.
This separate switch and techniques have proved very useful to overcome the
problem during most starts.
I'm too embarrassed to tell you how many times that the sprag clutch has been
changed,
or more specifically how few hours have been flown between changes, but
I'm keen that it shouldn't happen again. So now I've bought an additional
lead-acid
battery booster pack to assist the aircraft's lead-acid battery particularly
with the first start of each day during cold weather.
I'm not planning to move the battery forward into the engine compartment again,
due to C of G considerations and also because when it used to reside there the
kick-backs still happened sometimes.
Remi, your explanation of "kick-stops" due to a poor battery is new to me and
seems
to be a reasonable hypothesis. So from now on I'm going to change the battery
more frequently and use the booster pack as appropriate. Many thanks to both
of you for the quick responses.
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http://forums.matronics.com/viewtopic.php?p=487875#487875
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