Engine running issue.

[2robinhood]

I am running a DLE-55 on stock muffler, Bowmen ring, Falcon 23 X 9 prop.

Idle of 1500rpm with a top end of 7050rpm.

Diaphragm line pulled into fuse ( NOT INSIDE A BOTTLE ).

Engine runs great except in one maneuver.



I can roll inverted without any change in the engine.

I can even do inverted slight negative pushes without any engine changes.

But if I push hard inverted negative push, the engine goes into major 4 cycle / load up.



Now an upright hard negative push doesn't seem to affect the engine.



It only happens when inverted ( cylinder up ) and a hard negative push.



Any ideas / suggestions ?















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[Naughty Monkey]

I had a ZDZ 80 that did that, although not real severe, just a noticeable change when pushed inverted. RCS said to shorten the lever spring just a hair, worked on that motor. Another thought is like the BME 115's puddling fuel in the reed cage. That seems like a bit of a different scenario though.

 

[nebwake]

Turn your carb around. My guess is the diaphragm is heavy enough that it gets rich when you go negative inverted. Bad thing is that you might go rich inverted positive g, but I know I pull inverted positive much less than inverted negative.

 

[yakken]

Run a tube off your metering plate to a balsa box in the fuse. You have to use a very thin balsa for the box so it breathes

 

[2robinhood]

nebwake;10785 wrote: Turn your carb around. My guess is the diaphragm is heavy enough that it gets rich when you go negative inverted. Bad thing is that you might go rich inverted positive g, but I know I pull inverted positive much less than inverted negative.

When engine was new, I flipped the carb for throttle hook up.

I'd have to do a lot to flip carb and hook up the throttle servo.

yakken;10788 wrote: Run a tube off your metering plate to a balsa box in the fuse. You have to use a very thin balsa for the box so it breathes

I already ran a tube into the fuse, but it is not in a bottle or box.



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[yakken]

That doesnt do any good if its not isolated from the pressure that's being built up in the fuse

 

[Bhughes]

You've checked your fuel system out I'm assuming. Clunk doesn't get stuck? Etc. air leaks ? I had a dle 30 when inverted it would act funny. Mine was the clunk lol

 

[Ant]

My DLE 30 was similar. Blenders,knife edge spins,pushing up hard from inverted would all snuff it out.

I did the metering valve mode,ran the hose into a pill bottle with a small hole in it, didn't do it, made static ports on either side of the fuse, didn't do it,ran the hose just laying in the fuse, nothing really worked. Now, I just don't put that motor through those maneuvers much. Not sure what the problem is.

 

[orthobird]

did you get it to work? if so, what was the solution?

thank you..

 

[2robinhood]

orthobird;17645 wrote: did you get it to work? if so, what was the solution?

thank you..

Not yet, need to replace the airframe and get it back in the air.

Plan is to increase pop off pressure.



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