Speedy-Gonzales

My Feedback: (202)

I agree. Sometimes it is just a matter of which engine was delivered to your door and "Murphy's Law". [:@]

Truckracer

My Feedback: (19)

I've been at this hobby for quite awhile now and have bought more then a few engines over the years. I've bought quality and I've bought cheap along the way and the "sort of" rule you stated above pretty much applies to all of them! In fact, it pretty much applies to just about everything we buy. Spending more doesn't always guarantee a trouble free owner experience.

Speedy-Gonzales

My Feedback: (202)

I'll agree on that statement too!!!!

Happy Veteran's Day!

karolh

So very true as I bought a Zenoah engine that ran quite well but had a ring gap of .037".

Karol

757jonp

My Feedback: (48)

Blackpowder..and everyone else too!

Just finished checking the timing on the DLE20 that threw it's pin. It was set right at 30 degrees. No problem there.

Weather was just great around here this w/e. I spent a lot of it just thrashing this Mojo/DLE20/Xoar17X6 combo to the limit. Plane weighs right at 10 lbs wet and it will pull it around like a rag doll! I can't prove it, but I wouldn't be surprised if I was exceeding 10K rpm at times.

No, I'm not going to back off of it one bit. It'll either hold up..... or not. Time will tell.

ahicks

My Feedback: (2)

You should be pretty safe with a 17x6. That and the 16x8 are likely the most popular props run on this engine?

BlackPowder

757jonp,
Thanks for the info. I set mine at 30 degrees. I will check the one that I've been flying tomorrow. It's on a GP Super Skybolt, 9.5 pounds spinning a 14 x 10 at 8500, but I'm at over 5000 ft.

Ernie Misner

Please correct me if wrong but I believe that just because we "set" the timing at 30+ degrees does NOT mean that is where the CDI unit will be timing the engine when running and up to top speed. The 30+ or whatever is just a benchmark which will give the correct timing of 27 - 29 degrees when running. Of course the timing is retarded much below that figure when at lower rpms.

And a DLE ignition unit will require more advance when "setting" the timing than a RCEXEL unit on the same engine. But once running at top speed they both give the same result, 27 - 29 or so degrees.

flyboy75

I design aerospace bearings for a living. It is a manufacturing flaw. The bearing failure / damage was scondary to pin fracture.

Speedy-Gonzales is 100% correct. QC in China is horrible. I suspect you are not the fist DLE owner this has happened to.

thailazer

I've never seen galling like that on a single cylinder engine. Doubtful the prop could turn it over after the failure. Might make sense to do some checking to find out if something else (like a missing thrust washer or mis-installed bearing) could have caused the galling and led up to the failure. Thanks for posting the photos. Very interesting thread and I hope you get to the root cause.

757jonp

My Feedback: (48)

Hey Ernie

DLE ignition is a RCEXEL with a DLE sticker on it first of all. When doing static timing, you are sensing the advanced position. The unit will not retard until movement (RPM) is detected (I believe the minimum is about 200 RPM).

BTW, I just received a new ignition from Hobby King that I ordered out of curiosity. $23.99 and got shipped with other stuff, appears to be what we know as RCEXEL with a "Paragon" brand name on it. Not sure what model it is, but more than likely it's an 01. Hopefully it has a more "friendly" ignition curve. I'll let u'alls know what I find out shortly.

BlackPowder

I set the timing at 28 degrees because that is where Rcexl recomends and also I believe that C&H does the same. So on other engines that I have used the Rcexl ingition on that was my startng point. I think that it makes it easer to start and after when its running I have no idea if it advances to make power. Thats how my race car ignition works. ? To quote Speedy I'm not an expert, I just read the instructions.

Cub Flyer Fresno

Is anyone monitoring this thread anymore? I have a problem I haven't been able to resolve yet:
I have a DLE 20 that refuses to stay running. So far I've disassembled and cleaned the carb, everything looks to be in good shape. I've replaced the ignition, I think it may have been bad since it wouldn't start at all. I've replaced the pickup. I've replaced the spark plug. Nothing works so far. The engine seems to want to start, once primed it will catch for a few moments, but surges and then quits. The longer I try it the worse it seems to get. However, I have been able to get it running, and once running it seems to run great. So maybe after trying a few hundred times it warms up and then runs. But when it cools down again, forget it! Back to square one.

Does anyone have any ideas? I have ordered a new carb and reed valve for it. After that it's practically a brand new engine! (Should have just ordered a new one.)

ahicks

My Feedback: (2)

Low voltage to ign. module? 6v.+ preferred - as measured with a load on the battery. In other words, are you SURE the battery is providing adequate voltage? Have you tried a different one?

Engines set up with the low speed too lean are/can be pretty difficult to start. This happens frequently to somebody looking for a "smooth" idle. This is a single cylinder 2 stroke engine. They do NOT have a smooth idle if set up correctly. It's actually pretty lumpy, and when set correctly the engines are really easy to start, even by hand.

Surging a couple of times then quitting is a lean condition, often pointing to issues in the fuel system - somewhere between the carb and the clunk in the fuel tank. This is often most easily found by watching clear/yellow/blue fuel line where any bubbles could be easily seen when the engine is run without the cowl installed.

Just some ideas. Hang in there. It's nearly always something stupid that you've somehow managed to overlook. These really are friendly little engines that have made a LOT of friends for quite a few years now. -Al

Oh, and last, don't be shy of starting a new post here.

Cub Flyer Fresno

One thing I haven't tried is eliminating the Opto Kill Sw.. One thing a buddy and I did today, besides mess the the needles extensively, was to check the plug once it wasn't even popping anymore. It was wet, indicating that maybe too much fuel was getting in.

The thing used to run great, always started with a few flips by hand. Then, in my now destroyed Sbach, it started acting up. It would surge as if I was on the throttle. Then it would go away... until it decided to quit while I was in a hover. Never has worked very well since. I'll wait for the new carb to get here in a few days... or weeks... or... 🤔 Dang Covid 19!

kmeyers

Yes to seeing new post in old threads.
After cleaning reveals nothing, usually we do a simple carb rebuild kit. Bad diaphragm is the 2nd most common problem.
Good luck you will succeed.

CK1

My Feedback: (60)

Cub flyer , I'm with the previous post about the carb rebuild . The inlet screen in the carb also needs to be replaced when you rebuild the carb. The screen collects fine material and restricts flow . It may look clean but replace it anyway.
Another thought is do you feel much compression when propping by hand ? I've reworked 2 DLE 20 engines lately that have had very low compression .The ring gaps were in excess of .034"(should be between .010 and .016 ) and the piston to cylinder clearance was .008 ( .003 to .004 is best) . . One of them needed a new cylinder and piston with ring . The other needed only a piston and ring and deglaze the cylinder. Both came in for hard to start and wouldn't stay tuned , both also had significant pressure leaks at the front bearing from the seal and between the crank and inner race .
Low oil content is a killer . Some are running 50:1 oil mix .Use 24:1 to 32:1 for better cooling , cylinder sealing and longer life.
If your ignition is good and you carb is rebuilt properly but you still have issues get the compression checked and also pressure test the crankcase for leaks .
These simple little engines can get complicated sometimes.

loweheiser

lean mixture or no oil!