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Bill, base on my experience and your rpm there is no doubt
you need the larger prop as you clearly recognize.
Here is something you may want to check. When
my Coldstart function got turned on (without a switch being moved - long story)
without me knowing it at the time - my engine would bearly run with the
manual mixture control turned full lean with both primary and secondary
on. When I turned off the primary injectors it ran fine on the
secondary only because, of course, there was 1/2 the fuel flow of the four
injectors. Your symptoms sound very much like mine. One
of my rotor EGTs would also nose dive. Why just one, I am uncertain - you
would think both.
The only thing I can think for you to check is to
put a voltohm meter between the pin to the cold start switch on the control
panel Pin 13 (probably could put it on the output pin of the EC2 pin
30 if that's easier) and ground. With both injector switches ON
there should be no ground at that pin it should show open on your voltohm meter
(or a high resistance). When you throw either injector switch off then
that pin should show a connection to ground. If it shows a
ground when the injector switches are OFF that could be your problem.
Actually, since I don't know the internal wiring of the EC2 this is just a SWAG
on my part. But, clearly if the cold start which functions when that pin
is grounded - shows a ground with both switches ON then I would bet something is
probably not right.
The other alternative is that one injector in the primary
set is sticking open intermittently at lower rpm?
Ed
----- Original Message -----
Sent: Saturday, June 02, 2007 8:27
AM
Subject: [FlyRotary] Prop loads on
engine
I have made my third test run trying to sort
things out. I concur on the need for a load on the engine. I have
borrowed a Sensenich (sp?) prop for the test runs, since my Catto prop has not
arrived yet. It is 76x60, and must be severely under propped (76x88 on
order).
I started the engine, throttle all the way back,
then one turn forward. Engine RPM on EM-2 ~ 2800. Engine was running rich, max
number of bars on mixture indicator. Tried leaning knob adjustment and it
helped some. Engine seemed to bog some so gave it one more turn forward,
then started playing with injector switches. Turning off the primaries, engine
smoothed out, and RPM shot up to almost 7000, this is with very little
throttle opening! Mixture went lean, and leaning knob had significant effect.
RPM would climb rapidly when I richened the mixture. I cannot get anywhere
close to the 22" manifold pressure for some of the adjustments called for in
the EC-2 manual. Will have to wait for the more aggressive prop.
You can see that Rotor 1 is bogging down until I
shifted to Secondaries only on the EGT plots.
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