Tired Old Man

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Jody,

Glow fliers DO seem to have a tendency to identify themselves through error....

82 blackbird,

You are correct. The way a Walbro works is that a fuel passage orifice on the engine side, or back side of the throttle plate, is exposed to the incoming air as the throttle plate opens up to expose it. All the air passes through the venturi of the carb and nowhere else. There are several fuel passages behind the throttle plate that become exposed to air flow as the throttle plate is incrementally opened.

82blackbird

My Feedback: (3)

What puzzles me is if the problem is too much fuel or the falling out of the fuel due to the lack of velocity, then why is more fuel going to help this? Would making this hole larger decrease the signal (less vacuum) and thereby cause it to run leaner. I just want to understand how the modification will improve the performance of the engine. I'm alot more familiar with air bleeds, emulsion circuits and boosters in larger carburetors but a lot of the theory is the same.

captinjohn

Has anyone tried the enlargement of carb hole like DLE says to do. If not, before you say it cannot work try it. Remember both Hi & low needles work together. You need to go back and fine tune each one a tiny bit at a time. I say try it....before you knock it. Capt,n

wohenzhuce

hohoho...seems few people out of control here.

I think this mod is meant to improve stability of idle. Anyway it works for me, my DLE30 was 2500+RPM at idle, or engine will easily quit from full throttle to idle. I sent engine back to factory and they modified it for me. now idle is around 1500-1700rpm and 100rpm power loosen is acceptable to me.

I also hope DLE could come out with a better idea soon.

jedijody

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I'm going to stop posting accurate and helpful information if noboby is going to read it.

Tired Old Man

My Feedback: (1)

Agreed. Start reading on the last two pages and wonder why you don't have an answer.

As to the other, yes, the high and low needles work together, but do you have any concept of just how far trhe low needle impacts the high? With some carbs the low impacts the high out to a little over 85% of the performance range. This little beastie out to about 60% or so. So how will enlarging a low circuit improve an already wet condition? You can lean the high needle until it's closed with no assist to the low. The high needle has, at best, only a minor impact on throttle performance below 3,000-4,000 rpm. Say what you will, but I just ain't buying into the statement at all.

82blackbird

My Feedback: (3)

I agree with you Tired Old Man. IMO I think the high/no idle problem and puddeling are interrelated. Again my opinion, until they straighten out the intake manifold there will continue to be problems. I don't think this is a carb/compression/timing issue but with only 46 years experience with carburetors/manifolds what do I know?

Tired Old Man

My Feedback: (1)

You are correct in your observations.

However, if the engine is installed only slightly different from a true inverted position there is no problem. The problem, such as it is, is that many do not want to install their engines in an offset manner. They prefer there be no holes in a cowl of a non scale plane, and if there are any holes, they be located in the usual places. That insistence makes it impossible for them to do an engine just slighlty different from what they maight usually do. Gas engines, being larger than a power comparable glow engine, require more space, and gas exhaust systems are not as compact as most glow exhaust systems. That is where the "problems" arise. People do not want the stacks from their exhausts poking out in a different place and they are at best reluctant to go to an exhaust manufacturer to design their own exhaust. They prefer to leave all that stuff up to dealers and manufacturers. Then you have the potential throttle servo location "issues" where the modeler would have to make their own servo mounts instead of using the typical flat floors and pre-cut openings provided in the aircraft kit.

So much of the DLE 30 "problem" is not a problem at all when viewed from another perspective. It does not require any new parts or redesign, nor does it require internal modifications to the engine.

arobatx

If we didn't have challenges to overcome, we wouldn't be modelers, and this hobby would be entirely too cut and dry, and bore many of us. But I do understand there are some that want to plug and play and fly. No harm in that, but some education and understanding is still required. Good post Pat.

platero

Hi guys
I understand that an engine must to be plug_and_play, I have 40 years of hobby and never was needs to modify any engine, except weed eaters ones.
I have the DL 30, idle at 1800 rpm, but in 1 or 2´ the engine stop; I don’t like this in a new brand one.
But I get what I have paid. I don’t like to modify timing or Walbro holes, it gives fear me that the shaving falls inside the carburetor, etc.
I have a lot of gas engines, so I will think about changing it by one of that already I have.
Bad luck
Platero