Len Todd

I have two DLE 111s. One is a spare with a few hours on it, at best. While flying earlier this year, the one in my Extra backfired and quit. It blew the canister's inlet off and damaged the reed pedals. I replaced the Reeds and soldiered the canister inlet back on. These are the DLE canisters. It flew O.K.for the next two flights.When I got it out last weekend, the engine was frequently dropping off one cylinder until I reved it a bit. I flew it and it quit midair . But the prop bolts were all sheered off and I deadsticked it in.

So, I started trouble shooting. I swapped in the Spare engine which was previously running good and experienced the same problem. One Cylinder would drop out after about a minute of idling. So I replaced the gas, cleaned the fuel filer and tank, checked the voltage from the Smartfly Fiber optic regulated kill switch to the CDI. Voltage was good. There was nothing in the fuel filer. I even checked the Clunk and it was clean and open. Still the second engine was doing the same as the first. I swapped out the CDI's = same problem. I took off the cans and put on the OEM mufflers = same problem. There was nothing else on the plane that was common to the the two engines that had not been checked. I took the engine off the plane. It does the same thing on the test stand. I have cleaned both carbs several times. I even put in a rebild kit.Screen is clean and all orifices were rodded out to ensure they were not plugged. The carbs were soaked in cleaner for a day.

After all this, the left cylinder still drops out after a few seconds of idle. The Plug is showing me that it is wet. I have replaced plugs several times with new ones. The plane will not run correctly at the factory settings.The low speed jet has to be leaned about 3/4 turn to keep the plane running smoothly at mid-throttle. So, I would think it is a carb problem. But I'll be darned if I can find something wrong with either carb and I have rebuilt many carbs successfully. I am going to try a new ignition module and a new carb. If that does not cure this, both Engines are headed for the trash! I do not know what else to do.

Problem is the carbs are on backorder,again. So I spend another summer waiting for parts and troubleshooting engines. This is getting old. Time to start looking for a new hobby.

w8ye

My Feedback: (16)

Tower and Horizon both operate a back order business. To play their game - you had better get the parts you need on back order or you never will get them. For the parts are always on back order. Tower and Horizon are separate business but The two owners started out together within one company in the business world.

Sounds as though your metering valve arm in the carbs are either set too high or the needle and seat of the metering valve is leaking.

Len Todd

Regarding the Metering Valve Arms. I can not blow thru the fuel inlet. So I assume the Metering Valve is closing. Why would the arms on both engines change from their original settings?

I am not sure what the spec is for that setting. Is there a rebuild procedure for these carbs?

w8ye

My Feedback: (16)

If you cannot blow through the fuel inlet, the needle and seat of the metering valve is seated.

Typically the arm resting on the diaphragm should be level with the surface where the diaphragm/gasket seats.

Len Todd

I watched the walboro video on setting the arms. The first one was set at 6 pounds and the second one was 4.5. I set them both at 5 per the spec. However, there was no change. The left cylinder kept cutting out. I then reversed the spark plug wires to see if the miss-firing cylinder swapped to the other side of the engine, which it did. I think I have two bad CDI boxes as they both act the same way. What PITA seeing how they both were running just fine until this problem and then the problem showed up on both engines.Anyway, I am now certain it is a spark issue. Too bad I did not think of the swap before I spent three days on this. Dang.

w8ye

My Feedback: (16)

+1

cessnaflyer54

My Feedback: (68)

I would contact Desert Aircraft and get a carb from them. One off of a DA 100 fits right on and most likely will have the carb in stock. It's a better carb anyway.

Truckracer

My Feedback: (19)

Also, if a carb is needed, the Walbro WJ-71 is readily available from several Ebay sources at very reasonable prices. I seriously doubt there is a carb problem though if two engines have the same problem

speedracerntrixie

My Feedback: (29)

I would do a compression check on both cylinders. I doubt a carb issue. The carb is obviously getting fuel into the engine, the dead cylinder is getting wet right? I'm betting the dead cylinder has low compression that prevents it from firing. How close are the serial numbers? Could they have come from the same run?

ahicks

My Feedback: (2)

Can't help but agree. Not that I have a lot of experience wit this engine, but this test/check is pretty much telling the whole story.

speedracerntrixie

My Feedback: (29)

Yes Al, you are correct. Somehow I missed that. Usually in this case it's a bad cap. Easy enough to replace a couple caps though.

Len Todd

I have a new spare cap replacement kit. However, I just ran out of time to frog with it. Had to take a trip to Quebec. Will try replacing the cap Monday. Our club is putting on the West Michigan RC Expo Thursday - Saturday next week. So I hope I solve this soon. It has been a PITA.

WRK

My Feedback: (2)

wondering if you got it fixed and if it was a bad cap....................

Len Todd

Been the last four days setting up and running the West MI RC Expo. Have not had time to mess with it. Maybe today if I can recover from the last four days.

captinjohn

Maybe it is a bad boot inside the cap. Look for a crack in boot & spark traces.

Best Regards John

bcchi

I hope you have installed new NGK CM-6 spark plugs in these engines.
BC

Len Todd

I replaced the CDI box on the one engine in the plane and the problem disappeared. Of course the caps were replaced also. Then I stuck a piston at a show. Somehow, I had the thing running too lean in 105 Degree F ambient temps and lots of noise. Swapped in the spare engine and all was O.K.

I have not had the desire to replace the caps, yet. I did replace the piston, ring, cylinder, pin, bearing and clips. I'll probably get to the CDI's Caps this winter and give the two old CDIs another try in the spring. I typically fix in the winter, unless it is one of the show planes.

I also noticed that one has to be careful when installing the caps on the plug. If there is too much spring inside the cap once it is installed, the caps do not fully engage the plug's tip.