Dle 40 twin

[Michael Black]

Hi all a bit of advice please.
I have a dle 40 twin this was installed from new in a pilot Extra
It never ran right from now seems to bog on acceleration no matter how I tuned it. I thought it was just running in but it got worse and started cutting out never overcome it end eventually lost the extra when  it cut on take of and hit a fence. I left it for a while then put it in a hangar 9 ultra stick .
I’ve tried 2 different carb and 2 different ignitions I’ve lapped in the reed valves still the same probably a bit worse cutting at tick over. 
I noticed fuel dripping out of the carb so I tried with the model upside down so the carb is at the top and it seemed good. Any advice on how to get it working the right way round?  I guess fuel is siphoning into the carb The tank is as low as I can get it. 

Sorry for the essay

[Engine Doctor]

The fault will be in the  carb. Check the needle valve in the carb is seating properly or does not have some debris in it. No fuel should dip from carb as the needle valve should only open when allowed to by the diaphragm. The diaphragm should also be changed while your there. A quick simple check.

[Michael Black]

Thanks for the reply engine doctor I have looked at the needle valve and it seems okay I’ve sent for a new valve spring etc and a gauge to check it’s right. I am tempted to buy a new carb because this has been like this from new so maybe a faulty car, just don’t want to spend £60 if it’s the same when done

 

 mick

[Engine Doctor]

It's always a dilema whether  to replace expensive bits without a definitive diagnosis. The fact that fuel runs out of the carb when standing is indicative of a faulty nv. A service kit for the carb will only cost a few pounds and it's a simple job to do prior too fitting a new carb . They contain new nv I ternary filters and diaphragm plus all gaskets. They are available on ebay . The dle carb is a copy of a walbro . Not sure what carb is but the "wt" series seems most common on small petrol engines. 

Also buy a metering lever setting tool to set up the height of the lever that acts on the nv (metering needle).

[J D 8]

   When working on petrol strimmer's and other such tools with walbro carb or copy it is said that genuine Walbro service kits are worth the extra couple of pounds even if fitting to a copy.

[Michael Black]

Hi thanks for the replies guys bit of an update. I noticed the engin ran better when the plane was upside down, so I span the engin round so the carb was at the top and it ran really well but I notice fuel spitting out the top where the high speed port is of the carb. I but the engine back in its correct position with a velocity stack on it it ran great managed to fly in 40mph winds ?.  2 questions have I just covered over a problem still there, could the brass nozzle be installed/drilled wrong? 
 

Mick

PS my meter needle setting gauge turned up the needle is set spot on

[Engine Doctor]

Brass nozzle ?  A picture would help.

Its perfectly normal for a fuel mix to be expelled from a carb when running , especilally at full throttle . A Velocity stack will prevent this and increase fuel economy as the mist is captured and then burnt in engine instead of blown away and making a mess.

[Paul De Tourtoulon]

Have you checked the pop up pressure and the height on the main needle I set the pop up pressure at the 1 kilo mark.

 you also might want this tool,,https://www.fruugo.fr/diaphragm-carburetor-metering-lever-adjust-tools-for-zama-for-walbro-500-13-1-w-carburetor-metering-lever-tool/p-75947589-153432623?language=en&ac=croud&gclid=CjwKCAjwve2TBhByEiwAaktM1NLCzOMA04KOtnnkvKmfpcTRheD9mtRvu93NYrI91859UjtalgzfFxoCVcwQAvD_BwE#

[Michael Black]

Hi ED 

it’s the high end jet I’m Im used to just seeing a hole this has a brass jet. Hi Paul yes bought one of the meter needle level tools and it’s fine. Haven’t done anything with the pop off pressure