I am having trouble with my DL 50 in a Yak 54, and would appreciate any suggestions.
The top end is set to peak RPM, and the low end transitions to high speed immediately when the throttle is advanced.
The problem is with the mid range burbling, and hard starts. I flip it 30 times full choke sometimes and nothing. I have pulled the plug after many flips with full choke, and the plug isn't wet. Warm restarts usually require choke. The electrode is a medium tan color.
On my last flying session, I had 2 dead sticks after a maneuver. Up to now I haven't had a dead stick in 7 gallons of fuel.
The carburetor is vented into the fuselage. The cowl is baffled to only allow air to go directly through the cooling fins, and the exit is several times larger than the intake. I put a large louver at the front of the exit hole to create negative air pressure in the cowl, to promote a good air flow of out of the cowl. I also installed one of the black plastic venturi on the carburetor.
The timing has been checked, and is right on.
I am running Viton tubing, and two fuel filters before the tank. All tubing connections are zip tied.
I run the Xoar 22 X 8, or Vess 22 X A or B for the prop, and use regular gas with Penzoil air cooled.

Thanks in advance,
Greg

Doesn't anyone read this thread any more?

Greg

Hi Greg,
If your using a known good plug and your problems have only recently started,which it sounds they have,check the carb regulating diaphragm is soft/supple and not deformed/stiff,whilst your at it check the pump diaphragm and flap valves are supple and not deformed as well.

Craig

Not really a reason to. Most have moved on to the DLE 55.

+1

Carb might have dried out internally, and a rebuild kit might just be the cure.
VVRC -or- TBM should have them, ask.

My old DL50 starts and runs just fine.

RCWI and OldRookie what ya'll describe sounds like diaphram and carb problems. OldRookie your carb is not drawing fuel to it so if your fuel filters are not pluged and no leaks check the needle and the pump diaphram. RWI sounds like tuning L/H your high is lean and your low is still rich. The temp has been stated in other forms can't remember where that 300 degrees is a sign of over heating. I will check mine next time out and let you know.

Thanks all for your replies.
I'll start trying some and see what happens.

Greg

Rebuilt a DL-50 last week and used a Walbro K20-WAT kit in it. I didn't notice the number of the carb

What is the difference between the K20-Wat and the K10-WAT?

Greg

About the carb drying out....leave at least a 1/2 tank of fuel in the airplane fuel tank. Even flood the engine out while idling on the last flight of the day. It will retart the next time out super fast....like right away. Give it a try if you do not belive this advice. Capt,n

1/2 tank? Nah. Waaay too much.

I make it a practice to keep most gas out in my shed with the yard equipment, away from the house.
Most of my models hang from the ceiling or walls in the garage, which is attached to the home.

There's a safety factor here that too many ignore!

Just an ounce/1 ounce or less, in your models, will do just fine to keep things ready for the next flight.

I bought a J-TEC rap around for my DL-50 back in 2007. I used it for one season and the down tubes cracked out of the can. So I put it on the shelf and kind of forgot about it. Well about a month ago I started bulding a slick 540 and I wanted a pitts. So I emailed J-TEC telling them my story about the muffler and its cracks. They told me that I bought it a long time ago but send it to them and they will see what they could do. Well, they got it and said they could and would fix it. I thought that was amazing since I bought it so long ago. I also told them that I wanted a slick muffler and that I didn't have a plane for the muffler they were fixing for me. Then they said that instead of fixing my old muffler, how about they just give me half off a slick muffler instead. Because that is the muffler I wanted in the first place. So I got a brand new Slick pitts for half price!! The guys at J-TEC are the best guys to do buisness with. I am very happy with how I was treated. And they have a Raving costomer for life. THANKS J-TEC. Keep up the good work.

If you did not get the first one back, you got a slick muffler for 1 1/2 times the price.

He stated he used the muffler for one season . Right? So that means he got the second muffler for half price. You misconstrued the good part of people helping and giving of themself. Do'nt knock it.

Ok, i've run this eng up to 270 deg F. I think I've fried it. What are you guys thoughts?? the inside wall of the cylinder head has burned dis-coloring the darkest area is right below the exhaust. I have cleaned inside the head with degreaser. i cant feel any scaring with my finger on the walls.... I've jus been chasing needle settings. but every time she warms up a bit she wont start back up...

RCWI what oil and ratio were you useing in the engine?

40 to 1 penzoil

The ring looks a bit tired - showing blow-by. Should be clean all around. Piston looks OK from this angle.

Needs a massive cleanup!

You might get away with just a new ring if the rest looks OK after cleaning. Main bearings still good? Doesn't look knackered, just needs a bit of TLC.



How many miles does she have?

Yea I think the berrings are still good, "no play in them". and she has about 8 gals through her

That's not a lot of miles. Mine has had several YEARS of running on 40:1 mineral oil.

Got a (close up) pic of the plug?

I have a Question. I installed a dle-55 on a carden yak 89". i have about 2 gallons of 32:1 lawnboy ashless mixture through it. i also put a velocity stack on it. Problem is, when flying around, 1/2 or full throttle, the engine seems to backfire, i mean it really seems more than a simple burble. it has not stalled yet but sounds like it is real close when it does this. it does it in level flight, vertical, inverted, pretty much anytime and almost all the time. does any one have any ideas about what may be going on ? my first dle-55 is on a gp cap 27% and never had an issue like this, just smooth running. please help.

You might want to verify that your timing is not too advanced?

Please forgive the ignorance, but i dont know how to do that, could you explain please?

Here's a video of how to......
http://www.youtube.com/watch?v=GBXFp...eature=channel

I have a 3 year old DL50, been sitting for a year, I was wandering if it's too much engine for a 27% cap 232 , I'm not concerned about the power (throttle management) I'm thinking about the weight, any advice or suggestions?