ahicks

My Feedback: (2)

You said it was doing the same with 2 different carbs?
The top of the metering valve lever - is it flush with the surrounding surface? If it's low, or there's not enough spring tension, it would cut off the fuel flow.

You should be able to "rock" or "bump" the the prop up against the compression stroke and see movement of fuel in the fuel line.

Truckracer

My Feedback: (19)

My vote is for the internal passages being plugged. Even if you had no pulse for the pump, when choked the engine will pull fuel through the carb if everything is working OK. It won't continue to run if it pops, but it will pull fuel when choked. What happens when you crank the engine with the choke on and a finger firmly closing the air intake. Does it draw fuel then?

You may have to remove the welch plugs in the carb housing to get at the metering passages and check valve parts. That carb probably uses a capillary screen type of check valve and they can get plugged with crud. Before doing that, you might just try removing the needles and blowing parts cleaner through the passages looking for liquid flow through each drilled passage and especially through the nozzle into the venturi. I prefer brake clean over carb cleaner for this as it is less damaging to a rubber check valve should you have one. Follow with compressed air. You should know in short order if you have any plugging. Good luck.

kmeyers

microdon2

It used to run great.

When ever I see these words followed by I rebuilt it and it does not work, my first idea is to go through the rebuild from start to finish and make sure there are no mistakes.

Even the most experienced person can make a small mistake that causes a problem like you are having.

Truckracer

My Feedback: (19)

kmeyers, I couldn't agree more and I say that with no disrespect to microdon2 or anyone else. For example, I think I have a pretty good grasp of our little carbs from working on them since being a teenager quite a few decades ago, but every once in awhile, I screw up something really dumb during reassembly. It doesn't happen often but when it does, it is sure makes me look like a real dummy at the field. It usually happens when I get in a hurry and overconfident when working on an otherwise simple problem. Oh well ....

MTK

I get my stand offs from McMaster Carr. The size I use is 3/8" aluminum hex with female threads in both ends. I have also used 5/16" hex with no performance difference plus these are lighter. Either size is lighter than the typical stand off we see included with gas engines. Very inexpensive too. FWIW

ahicks

My Feedback: (2)

So it occurs to me after reading this, that if the assembly order of the gasket and diaphragm are reversed, that pump doesn't work worth a darn.

darkith

I had a DLE-20RA come new from the factory with the metering diaphragm and gasket installed upside down...wouldn't draw fuel when I tried to start it up, even if the tank was pressurized. Flipped the diaphragm and it started on the first spin from the starter. :P

D.

microdon2

My Feedback: (47)

Looks like I did have the gasket and diaphragm reversed, though fixing that didn't make a difference in the "manual pump" test (and that was after re-assembling it a few times, so it was probably correct to begin with). I then got carb cleaner and sprayed every open hole (after dis-assembling, including removing the welch plug (a first for me). Just put the engine back into the plane and - after five pumps - VOILA!! FUEL up to the carb! Too late to start it tonight, so am bringing with me to the field in the morning. Will let you know. (I'm going to have to re-tune, I'm sure.)

microdon2

My Feedback: (47)

The DLE 30 (mounted on a 73" CG Sukhoi) ran great this morning. I just had to open the L and HS needles a bit, but it spun the APC 18x10 beautifully. Maybe it was the carb cleaner ...

What's interesting to me is that hand-turning the crank shaft (with no prop bolted on and the engine and gas tank not mounted in the plan) did not pull fuel, but, as soon as I tried it while mounted on the plane, with a prop, it did (in 5 prop flips). Is it that the latter setup produces more torque \ pulse \ suction somehow?

Lifer

My Feedback: (1)

More rotational speed is what helped pull fuel. I've had good luck with my DLE 30. It really came alive when I installed a Bowman ring. Mine is mounted on a H-9 Taylorcraft and I use a Master Airscrew wood 20x6. Plenty fast for realistic acrobatics, good vertical, and aerobrakes the plane at idle.

microdon2

My Feedback: (47)

Since I've been using Synthetic oil I'm thinking of moving from 32-1 to 40-1, for better engine running and performance. I know the DLE's are recommended for 32-1, but I'm thinking that's more for natural oil \ break-in. Any comments? I'm also switching from Echo to Redline.

Thanks.

ahicks

My Feedback: (2)

I might consider the 40:1 move on the 30, but the 20, my feelings are that might not be a good plan.

First, there is no performance to be gained by the move.

Second, maybe not as much an issue anymore, but the 20's were taking out their bottom ends pretty regularly when they first came out. With the first reason in mind, and the potential for that bottom end letting go, my engines will stay on 32:1, dino or synthetic.

Truckracer

My Feedback: (19)

I agree with ahicks, there is little or no performance difference between 32:1 and 40:1. You may save a few pennies on oil by using less but performance isn't a valid reason to change.

microdon2

My Feedback: (47)

Ahicks - thanks. When you say "the bottom end" of the 20's, do you mean the needle bearing pin in the crank shaft? One of mine let go a few years ago. It does sound like the 20 is doing a much higher RPM than the 30 / 35. Is that why you're sticking with 32-1?

microdon2

My Feedback: (47)

btw - I've heard a few guys talk about a better \ smoother running engine from switching oil's, and pretty sure some of them were on 40-1. Would the oil quality make a difference, but not the ratio?

Truckracer

My Feedback: (19)

I've tried several of the trendy oils over the last few years ... from straight petroleum based through the synthetics and I can't say that any of them ran much different from the others as far as performance, reliability and smoothness were concerned.

Early this season I switched to Red Line Racing synthetic but mostly because it is far cheaper and more readily available than the previous oil I was using. Strictly a matter of convenience and economics. So far I have been very pleased with this change and I run it at 32:1 in every air cooled 2 stroke I own from airplane engines to lawn equipment. Just a personal preference and Yes I ran 50:1 and 40:1 for a season or more each in years past.

ahicks

My Feedback: (2)

Yes, 20cc crank pin/lower rod bearing need that extra oil IMHO.

Leaner oil mixture running smoother (32:1 vs. 40:1)? That's a stretch in my experience. If you want to run the leaner mixtures (even 50:1) in the 30, go for it. I don't see the advantage, and having multiple mixtures laying around (for all my gassers) is something I'm too lazy to deal with.

I use quality oil that's reasonably priced that I don't have to go too far out of my way to get.Used to be pro this oil or that oil, now I just don't care. If it's good oil, you'll be fine. Dino, synthetic, or blend, whatever..... Pay attention when you're mixing it up, and the engine will last.

shorte

I just bought a new dle 30 from tower and now the hole where the pin is on the crank case goes completely through the case. Now you can run a choke line through it to pull choke on and off. Wish they did this on the earlier ones.

3DMON

My Feedback: (39)

That's good to know. I wish they would do this on all there engines.

Truckracer

My Feedback: (19)

The early ones were that way also, they just had a steel roll pin in the hole. Remove or drill the steel pin and run a choke wire through the hole. I have two of the early rear intake engines bought in late 2010 and both are fitted for a choke linkage in this manner.

cymaz

karolh

No, it will not.

Super08

My Feedback: (2)

What he said, no effect....

kgeb

karolh

Semantics.