Bob,
Sorry to hear about your engine woes.
>From my experience in the shop here are some things I've run into:
Check that there is not 912S restrictor in your return line for the 914.
The restrictor is necessary in the 912S but Rotax forbids it in the
914. Make sure the return is not pinched either. See your install
manual on line with Rotax.
Don't make the mistake of swapping the fuel intake line and return
lines. (Believe it or not the engine runs, but goofs up the fuel
metering as one would expect, and won't accelerate properly or hit top
end.)
I hate to admit that I have seen one fuel pump hooked up backwards
electrically, and due to plumbing wouldn't feed enough fuel for full
power, but it would start...
Check your airbox and static pressure sensors aren't clogged or kinked,
or worse yet still plugged.
The new 914s have the removable fuel pans, and easy access to the float
bowls. Pull them and check for crap.
If dirty, get a rebuild kit and clean up the carbs.
Since you have 10 hours on your engine, it may be a mute point by now
but fuel quality is a combination of the source and materials quality in
the plane... Fuel lines are not shipped clean and there is residue in
them as well as the tank. Fuel with ethanol will clean better than Av
gas.
FBO's do filter their gas to a very high standard, but I find very fine
white organic material in it that my filters found, so think about pre
filtering your fuel. Since doing so I've had no problems.
My technique for assuring clean fuel tank and lines:
First. Get a pre filter funnel for your fuel. Fill the tank to the neck
with 20 gallons of premium unleaded with ethanol. Shake the aircraft
and check for leaks.
Next, disconnect the fuel delivery line at the engine fuel regulator and
pump the fuel back into the cans, alternating between main and reserve
sides. The filters will clean the tank. The pre tank filter funnel
will clean the fuel going back in. Fill again, and allow to sit. More
will settle, so repeat the fuel straining. Then I do it one more time
(total of three times) to insure tank and more importantly the lines are
clean. Fuel lines are notorious about being dirty. I don't use the
filtering gas for my first engine run, I Premium gas or Av gas.
While doing the above, do a flow and pressure check. I have a valve
hooked to the line off the aircraft fuel line with a T and fuel pressure
gauge to check for fuel delivery pressure and and volume. It is also a
good time to adjust the fuel flow measuring sensors. If you have in and
out metering, hook the delivery line to the return line and circulate
the fuel. Fuel flow should read zero. (912S owners can do this with
one fuel flow device and the restrictor installed and measure the flow
rate and pressure delivery with fuel returning to the tank.)
Bud Yerly
Custom Flight Creations
|