Hi Frans=2C
I don't know the 914=2C but your coolant temperature seems to indicate a pr
oblem. Usually=2C it is one of the three:
1) You changed the hoses and one or more clamps are not tight under pressur
e.
2) The filler cap is not fully tightened=2C maybe a clamp obstructing it.
3) Air lock
For carb balancing I used an electronic indicator from a car parts shop. An
y uneven combustion will cause vibration with a two-bladed prop. At least t
hat was my experience. The prop is already factory balanced=2C so don't mes
s with that.
Karl
> Date: Fri=2C 24 Apr 2009 22:47:49 +0200
> From: frans@paardnatuurlijk.nl
> To: europa-list@matronics.com
> Subject: Europa-List: First engine run=3B what is normal?
>
l>
>
> Hi everyone=2C
>
> Today I started the engine for the first time. It started right up!
>
> However=2C not being used to a Rotax 914=2C it is difficult to tell what
> engine behaviour is normal. There are two things that make me wonder if
> I fall into the normal range:
>
> 1) How rough is normal?
> Ok=2C I'm spoiled. Have flown most of my hours in a Cessna with diesel
> engine. 4-in-row=2C 3-blade propeller. These things run as smooth as a ca
r.
> With the Rotax=2C it is quite different. Vibrations are eminent. Have
> pneumatically balanced the carbs=2C checked everything=2C but can't get i
dle
> reliable and smooth below 1500 rpm. RPM is unstable (varies in a band of
> about 100 RPM above 1500 rpm=2C more below that)=2C runs relatively smoot
h
> between 2200 rpm and 3500 rpm=2C around 4000 rpm vibrations increase=2C
> didn't go any higher than that. Below 1500 rpm idle is unstable=2C and
> below 1400 rpm the rpm suddenly drops sharply. Had it for a short while
> running at 800 rpm=2C but=2C let's say=2C 1000 rpm is pretty much impossi
ble
> to get=2C most of the time it just dies if I try to get below 1400 rpm.
> The vibration is not that bad=2C it is not as if the machine is going to
> fall apart=2C but more like you would expect from a motorbike or so=2C we
ll=2C
> maybe slightly rougher. I have a two blade prop (Woodcomp SR3000/2W)=2C
> maybe it is normal for a two blade to give some vibrations? Haven't
> balanced it yet=2C but it is supposed to be balanced from the factory. Is
> this to be expected?
>
> Fuel pressure is 4 psi=2C RPM drop with both magneto's about 150 rpm
> (although difficult to establish because the rpm varies by itself).
> All 4 EGT's are equal. Checked the plugs=2C they seem normal as well.
> Front ones appear to receive a slightly richer mixture (see some carbon
> deposites=2C most likely from starting up with choke)=2C the bottom plugs
> show slight traces of oil on the outer ring. All show a pretty healthy
> tan color on the nose.
>
> Is this RPM instability and roughness normal?
>
> The engine has not been used since delivery around september. Could it
> be that I need to clean the carbs? Another possibility (not yet checked)
> is that I need to change the idle mixture (maybe somewhat enrichen it)?
>
> Oh=2C I did check the lifters=2C they appear to be functional=2C with no
air
> trapped inside.
>
> 2) How much heat is normal?
> I knew in advance that the combination Europa-Rotax is somewhat of a
> challenge. Have made some cowling changes with the expectation not to
> experience any heat problems. Alas=2C this thing heats up quickly. About
> 10 minutes before the coolant (50/50) gets to 130 degrees Celcius.
> Cylinder heads (measured with a ring sensor below the cylinder head
> bolts) about 10 degrees lower (?).
> In fact=2C I didn't succeed in getting an oil temperature up to the green
> zone (about 90 degrees) without getting into the red zone with the
> coolant. I doubt whether it will be possible to do some serious power
> testing this way.
>
> Is this normal? How long should it be possible to taxi/idle before the
> temps go to high? How should one test higher power settings on the ground
?
>
> Get about 750 Celcius on the EGT's at 3500 rpm (fronts a little bit
> lower than the rears). Is that normal?
>
> Have had the prop on fine with all tests.
>
> Any indications of what is normal are appreciated.
>
> Thanks=2C
> --
> Frans Veldman
>
>
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