oldtyme

Would it be a good idea to swap out the stock carb on the DLE20 witha Walbro carb and if so what Walbro carb would be recommended. I wouldn't do this if it is not necessary but just wanted to ask the question.

Thanks,
Andy

w8ye

My Feedback: (16)

I think the venturi in a DLE20 carb is close to 5/16" or a #20 Walbro.

I don't see any advantage of a genuine Walbro?

aussiesteve

IF you get your jollies from undoing 2 bolts then doing them up again, then you should absolutely change the carb out. In fact get a few Walbros with a #20 venturi on them and try a few out for maximum satisfaction

Ok - now a serious reply.
The DLE 20 carb realy doesn't have a history of needing to be changed out. In fact a number of other engines get improved by fitting the DLE 20 carbs to them. My recommendation would be to leave the original carb on there.

Are you experiencing any problems with it?

If you are, chances are it either needs the needles set (common cause of problems), the dirt cleaned out of it (another common cause of problems) or a basic kit through it (probably the worst case scenario).

sonny2

Obviously none of you are familiar with the inherent idle problem also and the linear throttle curve travel where the throttle butter fly only travels approximately 1/4 inch and the engine is already at full RPM. This has been a constant problem with the DLE 20 from the onset and Hobby Services who is the repair station for Great Planes have done nothing to help correct the problem. they just keep sending you under warranty a new engine or new carburetor, thinking you will solve the problem for them. And this can be dangerous also because on initial startup if you just crack the throttle and start the engine it will got right to full RPM's with just the crack of the throttle.....this is evident with the DLE carb. and not the Walbro

Truckracer

My Feedback: (19)

sonny2, quite a bit has been written about the DLE20 throttle issue. No reason to bring it up again here but you might want to read the several threads that exist on the subject. Here is a recent one .....

http://www.rcuniverse.com/forum/gas-...ent-dle20.html

Non-linear throttle response is not limited to the DLE carb but in this case the problem is often aggravated by the #4 ignition that was used on the early DLE20. The newer DLE20 throttles and idles quite well.

sonny2

But the E4 ignition really has to do with the idle problem and not with the linear travel distance of the butterfly in the carburetor which at just the crack of the throttle the engine goes right to full throttle.

sonny2

An the other problem is the people who should be able to answer to what the problem is, is the company that represents Great Planes, which is Hobby Services in which is the repair station for these DLE engines.
And you get no answers but just a song and a dance routine when you present these problems to them. You explain in detail what the problem is in reference to the idle problem and also the full RPM at just the crack of the throttle, and all they do under warranty is send you an new engine and this new engine has the same problem, like they think this will solve the problem and it will go away, with one of us will eventually solve the problem for them????

ahicks

My Feedback: (2)

Sonny, suggest that if you have a question regarding that engine, or any other gas RC engine, this might be one of the better places to ask it. Who better to ask than guys with many years small engine experience, and/or many, many hours in the air with the engine you're talking about?

You aren't the first to bring up the DLE #4 ignition. Many of us are pretty familiar with it, and the differences between it and the newer version. You might be surprised to know that once you understand what's going on with the original ign. module, it's possible to tune around it's issues and get a prettty good running engine out of the deal.

If you're going to a Walbro to get a linear throttle response, it's not going to happen. Can help with that too. In fact there's 2 ways of dealing of dealing with it. You can go a mechanical route, or use the electronic/throttle curve route.

sonny2

The mechanical route doesn't really solve the problem, but just by-passes the problem for finger feel, the carburetor butter fly is still opened ONLY approximately 1/4 of an inch at full RPM'S
......this has to be an air/vacuum problem perhaps, and such, in reference to the weep hole pressure plate for pressure relieve to the diaphragm for drawing fuel into the inlets.......The engine is a great engine, the carburetor is the problem........I have installed 6 of these engines for my customers, and the original engines only had the idle problem and I remedied this by adjusting the timing, But this is a problem I believe with the diaphragm not being able to do what it is supposed to do because of confined air flow over the weep hole of the diaphragm plate.....I am going to experiment with directing it's pressure relieve to the cabin area of the airplane by soldering a nipple to the weep hole plate and then tygon tubing from the nipple to the cabin area and see what happens......I don't know, perhaps this will work, because no one else such as Hobby Services who should know because they are the repair station for these engines for Great Planes and I have presented this problem to them for over a month now, and they keep procrastinating for an answer for the problem?? Ciao for now, if I come up with a solution, I will pass it on.....Sonny

ahicks

My Feedback: (2)

Yes, keep us posted.

Truckracer

My Feedback: (19)

Not happy with the DLE20? Buy a VV 20! It comes with a real Walbro carb. For the record, I have not seen a more non-linear throttle response from a DLE20 than any other Walbro or Walbro clone equipped engine. I'm thinking there is a bit of exaggeration going on here about how the engine RPM just jumps up with just a bit of throttle. Maybe the engine needs more prop load?

sonny2

With one click (white line) on the transmitter gimble throttle stick the RPM is already at 3000 RPM, one click from the half way (white line) the engine is at full RPM. I went from a 15 X 6, 16 X 6 with the now 17 X 8 prop and all it does is drop the RPM about 600 RPM and has nothing to do with the opening of the throttle carburetor butterfly. I took off the diaphragm weep hole plate and soldered a nipple on it to accommodate tygon tubing going through the firewall into the ambient relative air inside the cabin area and this had no affect on the problem.....Hobby Services is well aware of the problem and they don't give any solutions other than using the throttle curve. This is the 6th DLE 20 that I have installed on customers airplanes, and this is the only one that has this problem, and reading many reviews, this is inherent on many DLE 20's but not on all of them...The only difference on this DLE 20 is that the exhaust is on the side, and all of the others were in the rear.

Skinny Bob

My Feedback: (12)

I solved the none linear throttle problem by setting the throttle curve in the transmitter throttle set up. I am using the Tactic TTX650, I assume most trans have this feature.

ahicks

My Feedback: (2)

This in NOT an inherent problem by any shape of any imagination.

Have you had a look to see if the throttle plate is centered in the carb bore? The screw that secures it will come loose on occasion, causing some pretty weird idle speed problems.

Good logic will tell you that It can't rev if it's not getting air from somewhere. If it's at 3000 rpm+ at 2 clicks of throttle, you have a serious air leak. If not the butterfly, maybe the throttle shaft or carb body is worn to the point it's sucking air around that, cracked reed valve cage, etc.

Most common props are 16x8 and 17x6. Anything smaller will run way too high at WOT.

rcguy59

My Feedback: (8)

That's why they invented Throttle Curve in computer radios. Spend less time programming your radio than you did typing these posts and your problem is solved.

Truckracer

My Feedback: (19)

+1

JRgraham

My Feedback: (1)

I have replaced the DLE carb on my DLE 20 with a walbro, bought from Valley View.. same one used on the VVRC 20, and the difference is huge. The 20 now has a very sensitive throttle curve/range, idle is smooth and precise, no more hanging at high idle as before... just plain improvement.
Id suggest to anyone with a DLE carb to replace it with a walbro!

rcguy59

My Feedback: (8)

I wondered if a VVRC 20 carb would improve a DLE 20. I have both and the VVRC engine is much friendlier. I'll call Tom on Monday and get a VVRC carb to try. Getting rid of the #4 module IS a good start on the DLE 20.

sonny2

It's inherent because it is not peculiar with just my engine, The first engine has been replaced once (Hobby Services) and then they replaced the carburetor on the second engine, and the problem is the same with all 3 carburetors and there are many more engines out there in use according to all these reviews that have the same problem and they are solving them by doing the transmitter throttle curve. Which really doesn't solve the carburetor problem with the throttle butterfly still only being partially open when it is at full power after you do the transmitter throttle curve.

Skinny Bob

My Feedback: (12)

Sorry old man, but this is an inherent problem with this carb!, brand new out of the box, carb plate was fine not loose or bent. It would go full throttle at half stick. I had to adjust throttle curve to solve it. Are you running this engine, had any experience or just an assumption.

Skinny Bob

My Feedback: (12)

The throttle butterfly plate opens fully on my carb, I checked.
Bob

ahicks

My Feedback: (2)

Skinny, you're talking about something else entirely. You're referring to the fact that gassers don't have linear throttle response, similar to what you might find in a glow engine for instance. That's not something peculiar to the 20, it's completely typical for any gasser I've ever run using a Walbro, or a Chinese knock off of a Walbro. This is what we were talking about when discussing the need for a mechanical or electronic method to GET them to something closer to linear. Here there's very little more available after 50-60% open. That's just the way it is. It's not like you're going to be down on power or anything.

Sonny, yes or no. Were you exaggerating (or being dramatic?) when you said 2 clicks of throttle would have you at 3000rpm+? If yes, THAT'S an issue

Or are you talking about a throttle that's all in when the butterfly is at 50-60% open? That's normal. Get used to it. There's fixes available if you want to fix it - but changing the carb isn't one of them.

sonny2

I am running this engine and I have broken it in on the shop engine test bed. And yes, just a click under half throttle the engine is at full power. The engine runs great, but like I say it is peculiar to all other DLE 20's, the throttle butterfly is only partially open PERHAPS ABOUT JUST UNDER A 1/4 INCH AND IT IS AT FULL POWER......I have another DLE 20 right along side of it, and the throttle arm and the transmitter throttle stick are very relative to one another for travel, In other words on the good DLE 20 when the transmitter throttle stick is at 1/4 throttle travel it is at 1/4 RPM's, and when the transmitter throttle stick is at 1/2 throttle travel the engine is at 1/2 it's RPM, and when the transmitter throttle stick is at full forward travel the engine reaches full RPM power at the same time, which is normal and perfect.

ahicks

My Feedback: (2)

You would not be the first to replace a #4 module to make the engine a little friendlier when it comes to tuning. That's not to say a #4 is junk. Many guys are using still using them, without issue, myself included. The problem with them, and how to tune around it, has been discussed to death. I'll be happy to get back into it if your interested and can't find it somewhere....

sonny2

And what I don't really like about it is when you start the engine you just can't crack the throttle, because when the engine starts it is already at a very high RPM. And I don't exaggerate when I say it is at 3000 RPM's at just two clicks, and in fact I have learned not to crack the throttle because it will start right up at a nice 18/2000 RPM idle without cracking the throttle open.