RTK

My Feedback: (1)

Nothing better than a fresh pan sized trout on the plate

unclecrash

Did you make sure the gaskets to the intake are installed correct. A guy at our club turned one over and it blocked the pulse passage.

karolh

More than likely it's something fairly simple that's just below your radar causing the problem, like one that had me pulling at the few hairs I have left. Quite similar situation to yours, the engine would pop and run for a few secs. if primed via the carb throat, but just would not pull fuel. Turned out to be a partially clogged felt clunk.

Karol

azalner

My Feedback: (8)

The impulse ports are molded into the reed block on the DLE-30, both top & bottom. The gaskets are punched accordingly so it makes no difference - up or down.

Al

azalner

My Feedback: (8)

Good point Karol!

That was my first suspect.

I have been using Walbro felt clunks, and I even switched out clunks with a new one. Same result. I even pressurized the fuel tank through the vent. No go![]

Thanks

Al

SkyPilot101

Ah, If it was'nt for the small annoyances in life, we would all be having alot more Fun. Al, have you doubble checked the reed block, since you had block sanded it, it's possable you tightened the reed down too hard, maybe causing it to lift slightly. Add a few drops of two stroke oil down the carb throat to get the reed's wet. And cover the choke plate hole with your finger while you flip her over on choke.

RTK

My Feedback: (1)

Take a blunt object, pressurize the tank, then push on the diaphragm through the vent hole, fuel will flow, if it doesn't you have your answer.

azalner

My Feedback: (8)

Hey Sky

How you doin over there in Beaver County? Have you maidened your GSS Yet?

I'll get mine in the air if I ever get this dadgum engine to run.

Yup, double checked those reeds. I put a light coating of 3in1 oil on the blocks after I sand them and check for any holidays. Got good contact all the around.

Al

azalner

My Feedback: (8)

OK, I did as you suggested and low and behold fuel comes out of the jets when I open the inlet needle manually, but it wont draw when I crank! Got to be an air leak somewhere![:'(]

Al

CK1

My Feedback: (60)

Ok so the fuel is getting to the carb from the tank . You have pressurized it and unseated the needle and get fuel . You have checked the gaskets and the pulse passage for lack of obstructiuons.
You have verified thet the reeds are in working order (although they wouldn't stop the carb from pumping anyway).So it appears there is a leak between the crankcase and the carb pulse hole passage. It doesn't take much to loose the pulse through a warped reed cage or adapter housing . I would flatten the sealing surfaces by sticking some 400 grit paper to a piece of glass or other known flat surface and run the outer reed cage and the reed base over it to be sure the surfaces are not warped. If no warpage is found and you are possitive the gaskets are sealing then there must be a blockage in the pulse cicuit of the carb.

captinjohn

If the reeds are not sealing good ....that will make a huge difference on fuel draw. They are one way valves...so the crankcase can pump...that makes pulses that run the pumping section of carb. Take the spark plug out. Ignition off and spin that engine fast with a electric starter for 10 seconds. Then feel by hand flipping if it has crankcase compression at all. Hope that helps. Capt,n

CK1

My Feedback: (60)

Not in total disagreement captainjohn the reeds will make some difference but not much at hand flipping speed . There will still be enough positive /negative shift in pressure within the crankcase to to operate the carb pump even if you remove the reeds .

azalner

My Feedback: (8)

CK1 I think you solved the mystery!

After I read your post, I went down to the shop and looked at the reed block and the crankcase inlet. Reed block looks good and flat but the crankcase, hmmm... just a casting surface. So I took a smooth file and carefully drew it across the surface of the inlet. Lo and behold, the high spots are either side and the low spots are on the top & bottom, just where the impulse ports are. I took a photo to hopefully show what I am talking about. We're not out of the woods yet, but I can see light at the end of the tunnel. I'll put it all back together tomorrow and have another go.

P.S. I'm still going fishing tomorrow.

Thanks to all of you who chimed in. Very much appreciated

Al

SkyPilot101

Hey Al, Do'in fine up in Beaver

GSS got put on the back burner for a while, Too much of that nasty "work" thing again, bussier than it's ever been, so just petering around finishing up a re-build of A 120 Seagull Decathlon that I cracked up a bit last year

Hope you get the fuel draw prob sorted out, currious as to what you find. Mike.

azalner

My Feedback: (8)

Hello Everyone! I'm back.

After three walleye, three smallmouth, one largemouth and a new carb here are the results:

Put some Permatex gasket sealer on both sides of the gasket between crankcase and cylinder head AND installed new carburetor. Put the engine back on the plane and she fired right off and kept on running. End of story with a happy ending?

WRONG

This sucker will only idle down to 4700 RPM at full low throttle. Yes, believe me the throttle lever is physically back as far as it can go.

The only thing I can figure out now is that the lever arm on the new carb is set incorrectly allowing too much fuel to pass even at low throttle setting.

Anybody got any better ideas?

Al

RTK

My Feedback: (1)

Too much air is passing from somewhere if the butterfly is closed and it is still running, especially at that high of rpm

3136

Might be a silly question, but have you taken the idle screw out?
Failing that, I would get it running and spray aerostart around the insulator block and anywhere else a air leak is suspected.
look for rpm change.
If that fails take the engine out again and look at the carb to see if the valve is actually closing properly.

azalner

My Feedback: (8)

Let's see. I filed the carb inlet on the crankcase flat, sanded the reed block surfaces flat, installed all new gaskets, installed a new carb and sealed the joint between the head and crankcase. Its drawing fuel now where it wouldn't draw fuel before. I would think that I sealed up any air leaks that were inhibiting vacuum.

With that said, you're right. You must have the correct fuel/air mixture to turn 4700 RPM. Too much fuel AND too much air. Back to the work bench.

Thanks

Al

azalner

My Feedback: (8)

Idle screws have no place on airplane engines.

Is aerostart the same as ether based starting fluid?

Al

3136

Aerostart can be bought at auto shops, not sure what's in it.
Maybe spray wd40, you are just looking for an rpm change.
Check that butterfly is closing, you'll have to take it off the plane again.[:@]

azalner

My Feedback: (8)

Hi all,

We have at last come to the end of the story. After all new gaskets, sealed up everything including everyones suggestions on flattening the sealing surfaces. Got the engine running and it seemed to be fine on the high end but could not get the idle down below 2200 rpm. In addition it was surging at the lower rpm's which I didnt like at all. We could not get rid of the surge no matter how much we fiddled with the low speed needle. I finally threw in the towel and put on the new carb.

It started on the first flip and ran like a Swiss watch. Low needle at 1-1/2 turns out, high needle at 2 turns out.

7200 rpm with a XOAR 19 x 8 prop. Idles forever at 1700 rpm. Instantaneous throttle response - no burble.

Tomorrow I maiden the Giant Super Sportster!

Thanks to all for your input.

Moral of the story, don't mess with them carburetors!

Al

CK1

My Feedback: (60)

Al ,
glad you got it running , sometimes all you can do is replace a carb to cure a problem . too many little passages that are impossible to see or clean
Happy flyin'

ggraham500

My Feedback: (4)

Please let us know how the maiden went.

I have a DLE-20 in my GP Giant Super Sportster but have yet to maiden her. I know it might be a bit under powered by many peoples standard, but the Saito 150 I use to run the plane on was way more than it needed, so I wanted to try the DLE-20 rather than a DLE-30 (which I have waiting "in the wings").

microdon2

My Feedback: (47)

azalner - Did you finally resolve your issue? Or was that new carb the answer? The causes I've seen for lack of suction include a cracked manifold and also a loose throttle and \ or choke plate. The screw in the center sometimes loosens, and then the plate slips off-center - then you can't close fully. You'll never see it unless you're looking for it. On a Zenoah G-26 I discovered that the pulse hold was partially covered by the gasket (evidently a not-uncommon problem with Zenoah's)

On my DLE 30 I'm having a flooding problem - the engine starts fine, but then dies when you bring it down to low idle, then won't restart, and the plus is wet. I've worked with other, more senior gas pilots and it seems the low speed needle was having no effect. They suggested a carb rebuild, which I'm going to do.

Anyone know the right rebuild kit for this carb?

azalner

My Feedback: (8)

I bought a new carb. The time I spent trying to rebuild it was worth far more than the $30 for a new carb.