Engine Gurus Unite -> I need HELP!

[bob_nj]

Scenario is DLE 30 about 4 years old.
I didn't buy it new, and I don't fly it a lot, but lately here's the scoop.

Very rich on the low end no matter where the needle is.
If the needle is too far closed it dies.
Runs very rough on the low end and spits out black junk because it's four stroking.

Lean on the high end no matter where the needle is.
Starves and dies.

Changed the IBEC with a new one.
Changed the carb with a new one.

Fuel system seems fine
Ignition seems fine

The only thing I haven't messed with is compression/ring, and reeds.

Any ideas???

Thanks
Bob

 

[GaryToland]

Has the carb ever been cleaned?

 

[49dimes]

Pull the carb and reeds. Inspect the reeds for proper seating and that they are not broken or chipped. Replace the carb or rebuild it with a kit. Before doing this look at your plug or just put a new plug gapped .020" and make sure your ignition battery is good, Plug cap and insulator is good. Seems it is just not getting a good hot spark.

 

[GaryToland]

New carbs have been known to have stuff in the screen which can cause poor fuel flow, another possibility is blow by from the ring. I had it on a new motor with 20 flights on it. Ordered a Bowman ring and problem solved.

 

[bob_nj]

Gary -->
I cleaned and rebuilt the old carb and there was no change at all.
Still couldn't adjust the low end enough to get the four stroking out.
Installed the new carb and there was no change.
Engine acted exactly as before.
Can't adjust out the four stroking on the bottom, can't get rich enough at the top end

49 Dimes

Pull the carb and reeds. Inspect the reeds for proper seating and that they are not broken or chipped.

What are the symptoms of an engine that has bad reeds?
In essence, the needles on my engine are ineffective with an old rebuilt carb, and with a brand new carb.

Replace the carb or rebuild it with a kit.

As stated, I've done both.

Before doing this look at your plug or just put a new plug gapped .020" and make sure your ignition battery is good, Plug cap and insulator is good. Seems it is just not getting a good hot spark.

I should have mentioned that I did gap and replace the plug with a new one.
I'm using an ignition eliminator. I removed the original and replaced it with a new one with no change in the engine.
I'm guessing the plug and battery are good.
The plug cap and insulator "appear" to be in real good shape. Takes an effort to remove the plug wire from the ignition, so that is tight too.
I too started thinking electrical at one point. That's when I replaced the ignition eliminator.
I suppose I could try another ignition and see what happens.
It would just be nice if I could pin point an issue as opposed to throwing parts at it.
It just has me stumped.

Gary -->

another possibility is blow by from the ring

There is a lot of black junk coming out, but I thought maybe it was from running so rich.
I could get a Bowman.
Would a poor ring seat cause the ineffective needle thing?

Thanks for the ideas guys.
I'm takin it all in...

Take care
Bob

 

[49dimes]

Typically faulty reeds will make hard starts (if at all) inability to tune, poor transition, and failure to reach peak RPM.
If your engine has decent compression then the ring is probably not suspect other than it may very well be stuck due to excessive carbon build up (black gunk you are seeing). More often than not the ignition and weak spark cause all the symptoms you are describing. Like others have recommended in other threads see if you can get a known good ignition module and plug your battery (known good) directly to it and run the engine. If that fails to produce desired results then pull the cylinder and look for damage to the walls and piston.

 

[bob_nj]

I do have another ignition I can try.
I'll do that first.
I'm getting a Bowman, some new gaskets, a reed block and new reeds.
We'll eat this cow one burger at a time.

It starts great, and will reach peak rpm fine.
It just won't hold peak.
Just sags off and dies.
The transition is crap though. Stumbles and four strokes at low end.
Once it gets past that is when it will reach peak rpm, then sag off.
Go figure.

Thank you for your help!
Bob

 

[Capt.Roll]

Since this hasn't been mentioned............

I'm sure the DLE30 has a pulse port but not sure if it is an external hose between the crank and carb or if it has the internal small hole that runs between the crankcase and carb via a hole through the reed block. Check to make sure there is no blockage or restriction in the path.

Well scratch this, I have been informed the DLE-30 does not have a pulse port.

 

[GaryToland]

Gary -->
I cleaned and rebuilt the old carb and there was no change at all.
Still couldn't adjust the low end enough to get the four stroking out.
Installed the new carb and there was no change.
Engine acted exactly as before.
Can't adjust out the four stroking on the bottom, can't get rich enough at the top end

49 Dimes

What are the symptoms of an engine that has bad reeds?
In essence, the needles on my engine are ineffective with an old rebuilt carb, and with a brand new carb.


As stated, I've done both.


I should have mentioned that I did gap and replace the plug with a new one.
I'm using an ignition eliminator. I removed the original and replaced it with a new one with no change in the engine.
I'm guessing the plug and battery are good.
The plug cap and insulator "appear" to be in real good shape. Takes an effort to remove the plug wire from the ignition, so that is tight too.
I too started thinking electrical at one point. That's when I replaced the ignition eliminator.
I suppose I could try another ignition and see what happens.
It would just be nice if I could pin point an issue as opposed to throwing parts at it.
It just has me stumped.

Gary -->

There is a lot of black junk coming out, but I thought maybe it was from running so rich.
I could get a Bowman.
Would a poor ring seat cause the ineffective needle thing?

Thanks for the ideas guys.
I'm takin it all in...

Take care
Bob

Yes it can, because the compression is weak, the ring these engine come with aren't that great to begin with. You have had the engine for 4 years already and was used. Also as 49dimes stated be sure to check your reeds and make they are sealing properly.

 

[GaryToland]

Oh and check fuel lines as well, and the clunk line too. (Stiffness?)