gsmith6879

My Feedback: (37)

Guys,

We need some help. We have a number of DLE engine in the club that are performing very well. One of the guys recently bought the DLE60 twin to go on his Hellcat and is experiencing some weird problems with the carburetor. When he first ran the engine it started and ran great. Pulled the Hellcat like a mule. After about 6 tanks of gas it went lean and no amount of adjusting fixed the problem. He tore down the DLE carb and found a significant amount of hardened white gunk on the screen. He chipped that off and cleaned the screen. The engine then started right up and again pulled the Hellcat with authority. Six fights later the same thing happened. This time the screen was plugged with a soft gray gunk. Came off much easier. After cleaning, the same good performance returned....for another six flights. The same soft gunk but less of it. He has cleaned and replaced the entire fuel system...twice. He is using 91 octane pure gasoline produced by ConocoPhillips with Husqvarna 2-Cycle Synthetic Blend oil mixed at 40-1. The fuel mixture is filtered in the storage container before going into the ailpane. That filter has been checked as well. He has disassembled the carb and found no obvious cause for the deposits on the screen. He has 3 other gas engines that have had no problems.

Anybody got any ideas?

mpascual

My Feedback: (1)

Fuel can (must be for gasoline fuel, some plastic cans does not work well with gasoline)
Fuel tubes (tygon or gas proof)
Tank stopper (suitable for gas fuel)
Mix of synthetic oil , glycol and esther based does not mix well)

Best regards

thepamster

My first thought is anybody else using that same brand of gas with no problems at the fiekl? If not try different gas.
Second thought is what type of fuel lines and filtered clunks are being used.

krayzc-RCU

My Feedback: (31)

sounds like he is using a milk jug.....

gsmith6879

My Feedback: (37)

OK, let try this again. We are a club that runs mostly gas. We all know how to plumb a gasser and this guy is the most knowledgeable when installing gas tanks, stoppers, tubing, etc. The same gas and oil is being used by 3 other guys with no problems. The Oil is Husqvarna 2-Cycle Synthetic Blend sold by Lowes and is being used by most of us. This guy is running a 3W and 2 other DLE's with not problems.

Milk jug?

thepamster

Perhaps then there is a foreign substance inside the carb from manufacturing that is working its way through. After the next 6 flights there will be almost none left.

The Ghost

His fuel system is contaminated some where, be it his fuel storage drum, fuel caddy or aircraft system, this is the only way that will happen.

Cheers

krayzc-RCU

My Feedback: (31)

maybe his carb is made of some material that the gas is eating away at
the fuel stopper is labeled wrong

hey we are just here to help don't shoot us

1QwkSport2.5r

I agree. There is crud getting stuck in the carb and its coming from somewhere between the gas pump and the carburetor. I'd be checking and/or replacing fuel lines, filters, fuel tank stopper, and soak the carb in carb cleaner to ensure the crud is dissolved and removed from all of the passages.

gsmith6879

My Feedback: (37)

OK, one more time again. We have replaced the fuel system...twice. All components were for gas and were inspected for cleanliness.

A carb made from material that is not compatible with gas. It's a gas engine with a good reputation. Do you think?

The carb has been cleaned 3 times in including a good soaking in carb cleaner.

Using the same gas, oil, storage container, filters, etc no other engine presents this problem.

The carb is the logical source but this is way too much stuff to still be coming from the carb.

I'm done. Thanks for the help...I think.

We will continue cleaning or send it back to Hobby Services under warranty.

1QwkSport2.5r

With all due respect, foreign substances don't just show up some time after break-in. It's doubtful that these substances have been in the carburetor the whole time. I'm certainly not picking on you nor the owner of the engine, just trying to help as is everyone else here.

You didn't mention how or if the engine was bolted to a test stand and broke in. Was this done or was the engine broke-in in the air? If the latter is the case, then there is the possibility that there could have been gunk in the carburetor from new but after two cleanings and even soaking it should be clean by now. After the soaking in carb cleaner (not the spray can stuff I hope) the carb body and jets were rinsed and blown out with compressed air, right?

The stopper in the tank is black rubber and not white rubber?

thepamster

Help can only be as good as the information provided. It wasn't until the last post before you said anything about the carb being fully cleaned. Thats a fairly large piece of info don't you think.
If you have ruled out contaminated fuel system components, jugs, lines, gas, etc. the only thing left is the plane itself. Maybe the carb is sucking in something from the cowl. Some debris or film on the inside of the cowl. Was it painted by the owner, a baffle added that introduced a foreign matter of some sort. I certainly have never heard of this.
At this point I would like to see pictures of the complete installation.
But it sounds like you are done. So I hope your friend gets it figured out.

dingo9882

My question is this....could one of your bearing be going? It sounds crazy because it is a new engine, but it is possible. Maybe the bearing's lubricant or the race is going but he may want to tear down the engine and just peak in there. The reason why I say this is because it happened to me with a Brison 2.4

rednekk58

How would bearing material end up in the carb?

krayzc-RCU

My Feedback: (31)

its a 2 stroke look up some google pics

BUCKETOBOLTS

My Feedback: (1)

The hard white substance is corrosion from the moisture in the fuel. It doesn't just happen over night, but from storing with fuel still in the carb. As the fuel evaporates the moisture is left and builds over time. I always draw out the fuel left in my tank, then start the engine to run out the remaining fuel in the system before I leave the field.


Could someone explain how bearing material can go from inside the crankcase to the fuel side of the carb? I can see it in the venturi, but it would have to pass by the jets and needles to enter the fuel bowl side of the carb.

airraptor

My Feedback: (66)

the fuel screen in the carb filters the fuel before it goes into the carb. that is what it is for.

You have contaminated fuel, fuel can/jug/drum, a bad/contaminated fuel pump(to pump fuel in planes tank), or bad fuel lines from the fuel can.

Filter the fuel before you put in the plane. its not the engines fault it is something before the engine...

JRgraham

My Feedback: (1)

Not completlely on the topic, but Iwas looking at the DLE60 twin this morning on Valley View, and compared it to Chief's listing.. Iwas surprised to notice that in the Specs, Valley View has the DLE60 twin output rated at 7hp@ 8500 rpm, and Chief has it rated 5.5hp @ 8500 rpm..

Who is correct here?
Also, while Iam off topic, can someone post the measurment of the heads, plug to plug? Its somewhere around here, just cant seem to find it.

Thanks!

1QwkSport2.5r

This is sort of where I was going with my suggestions. I agree with airraptor on this one.

thepamster

http://dle-engines.com/dleg0060.html

The dle website shows hp at 5.5.

http://downloads.hobbico.com/misc/dl...dimensions.pdf

276mm plug tip to tip.

dadragon

Gaines;what a nice time to start a quiz,How is the A-1 doing.Geo.

JRgraham

My Feedback: (1)

Thank you much, pamster! What a brain fart to not go to the DLEwebsite, huh?

Iwas kind of hoping that the 7hp was the correct rating.. even though I figured it seemed a bit much. Although there was a thread where a guy put the DLE60 in a 96" extra designed for an 80cc, and it pulled it around very well..

[/hijack]

gsmith6879

My Feedback: (37)

Yea, a lot of good suggestions but everyone is ignoring the fact that the guy has 2 other engines he is flying weekly with the same fuel, oil, container, filter with zero problems.

The A1 is still flying well after almost 5 years. It is my favorite warbird. I did a bit of paint touch-up last month to get rid of some hanger rash and replaced the fuel system early this last winter. The G62 just seems to be getting better every flight. I have also replaced all batteries with A123 systems packs and the old nicad starter battery with a very light 1800mah LiPoly 3 cell pack.

If you missed it here is a video that a guy took for RCU at Warbirds Over Tulsa last year. It was windy and I almost folded a gear but it kept on trucking.

http://www.youtube.com/watch?v=JAgJtGzlMyE

1QwkSport2.5r

Well this DLE 60 should be running like a dream then. Unless there's a witch doctor putting a curse on it.

Crud doesn't just show up in the carb and keep showing up unless there is something getting into the carb. The fuel hits the screen first, so whatever this white/gray crud is, it's getting to the carb from between the fuel can and the carb screen. If it was a gummy carb to start with, all these cleanings should have taken care of it.

Oh, and the day a bearing inside the crankcase sheds gunk that gets into the carb is the day our dollar will actually be worth a dollar.

Just my overtaxed $.02

Mr_Grump

If you've replaced the fuel system 3 times, cleaned the carb and that didn't fix it, I'd quit wasting time and replace the carb, reed block and all the associated gaskets. It gets to the point all the second guessing is a waste of time and it's not worth the aggravation anymore. Granted, some of the parts are likely good but personally, I'd rather just get it running.....