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Message
But I’m in a bit of a
quandary. I set TDC on the flywheel
as Lynn described and it looked so perfect. But the timing light is showing it
firing at 40+Deg. ATDC and when I turn the Crank Angle sensor as far as it will
go trying to advance it I can only get up to about 20Deg ATDC.
Hi
Joe,
Static timing is just that
"static". Once you start running, your ignition controller decides where
it wants the timing to be relative to the static timing, so think of the static
timing as nothing more than a reference for the controller.
As you know, the faster the
rotor is moving, the less time the spark has to complete ignition, so you have
to advance the timing to start it a bit earlier, so ignition occurs in the
correct position of the rotor. Using the same logic, the timing can
be retarded at idle. For a complex controller like the
MicroTech, I would not be surprised to find out that they're taking
advantage of a larger range of timing than aircraft normally
use.
Now, I am supposed to
put the timing light on the #1 Leading plug lead, right? That’s what my Mazda
manual says.
That would be my
guess. I'd assume that it's done the normal, Mazda way, unless MicroTech
tells you otherwise.
I guess I’ll have to
see if I can re-position my Crank Angle sensor this weekend and see what happens
when I can advance it further.
I haven't looked at it
closely in a while, but I'm guessing you can pull the CAS, and rotate the gear a
tooth, then reinstall it. By experimenting with this, I'd bet you can get
the desired timing within range of the slot on the
CAS.
The MicroTech setup manual says to set the idle timing to 5Deg
ATDC – it also says that is the yellow mark on the pulley).
They're probably right
:-) At some point, you'll want to verify that the MicroTech is advancing
the timing properly at higher rpms, but if the
only timing adjustment they gave was at idle, then I'd bet a few
beers it's going to be right everywhere.
Joe
Hull (loving the smell of exhaust in the my hair, my clothes, my
skin…)
Might cut into your social
life though :-)
Cheers,
Rusty (XL pulling farther
into the lead)
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