DLE-55 running problems

[ibanezex718]

So I replaced the prop hub on the motor and put everything back together and fired the motor just to make sure everything was good. I ran an entire tank through the motor in my garage and no problems, I later put two successful flights on it with no problems either. In the middle of the third flight was where the problems started. First the motor would take a longer than normal amount of time to return to idle making me to back my throttle trim all the way back where it finally died once it caught up with itself.

Now the major problem is no matter what rpm the motor cuts out and almost dies and sometimes backfires, it seems like the problem is getting worse every time I run it. At first I thought I was getting bubbles in my fuel line, but I checked that and nothing wrong there. The fuel possibly could have gotten something into the carb, but I doubt that as I have a filter on my gas jug and a filter right before my carb.

Any ideas?

[Jedijody]

I think the filter screen in the carb is plugged up.

[wallygator]

Pull the hub again and check the woodruf key, is it there or is it sheared???
Timing may have slipped or you could have blown the seals.
Backfiring is a sign of a timing change or you could have a bad ignition.
Demagnetised the magnet??
Did you have the carb off?

[scott m lyons]

	Quote: Originally Posted by Jedijody
	I think the filter screen in the carb is plugged up.

+1

[eric g goble]

Make sure the vent line is not kinked,a lot of people run it around behind the tank and tie it with a tie strap. The tie strap can cause it to kink.

[ibanezex718]

I think what I'm going to do is pull the carb and clean everything with some gas and put it all together and see what that does. I checked all the lines and they are all good. Timing couldn't have changed, the crank had the key in it so the timing should be where it was from the manufacturer. I tested the spark and I have good spark so i don't think it can be that. If the seals are blown would this be something covered under warranty, or how difficult would that be to repair?

[Jedijody]

Take the engine off and take the fuel pump cover off the carb, that's the cover with one large screw in the middle of it. Carefully remove the pump diaphragm and you will see a round hole slightly larger than a pencil, in that hole is a very fine filter screen. Using a sharp pointed tool like an exacto knife, stick the edge of the screen and pull it out. Hold it up to a light and look through it, you should be able to see through it just like a window screen. If you can't it's plugged up, use some carb cleaner or gas and compressed air to clean the debris out of the screen and reinstall it in the carb, make sure you get it down where it is supposed to go and is even all the way around. Reinstall the pump diaphragm and the cover and the engine. Replace the filter you have before the carb and try it again.

[forgues research]

	Quote: Originally Posted by ibanezex718
	First the motor would take a longer than normal amount of time to return to idle making me to back my throttle trim all the way back where it finally died once it caught up with itself.

If the engine would take longer to return to idle, that would mean you are running very rich and not missing fuel.

Backfire, usually means ignition timing is off....

Roger

[Tired Old Man]

Roger,

I've found that engins that don't like to idle down (slow to reduce rpm) have been lean on the low needle.

[forgues research]

	Quote: Originally Posted by Tired Old Man
	Roger, I've found that engins that don't like to idle down (slow to reduce rpm) have been lean on the low needle.

could be but that would contrary to logic, since it has excess gas to burn.

Also a bad ignition system will not help either.

Roger

[Al Lewis]

Every engine I ever had that was slow to return to idle , or refused to without cycling the throttle, was due to a lean condition on the low end.

[JoeAirPort]

From my recent experience it's very easy to plug up the carb screens, and VERY easy to take the screen out and clean. Luckily I have my carb's rotated so the pump is on top. I just take the cowling off and I can service it. Anytime I see the engine start acting lean on the low end (too high of idle is one), I know it's the carb screen blocked. Piece of cake to fix.

[brycesteenburg]

Roger,
Your using the wrong logic here. Rich mixture loads an engine and has a slow, incomplete burn.
I don't want to get in a debate and get into the theory of gas laws, entropy, enthalpy but do some research on the design and tune of a heat engine and you will see that your logic is incorrect. No offense to you at all!

Bryce

[ibanezex718]

Well thats what I thought as well with the rich/lean mixture. So just to experiment with it I ran the motor really rich, then back to lean, and no matter what setting I have it at it still ran the same way.

[2walla]

Air leak...somewhere..